Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
For example, will rising levels of green OA trigger cancellations of toll-access journals? The primary drivers of green OA are policies at universities and funding agencies. Remember, all university policies allow publishers to protect themselves at will. (See section 4.1 on policies.) For example, universities with loophole or deposit mandates will not provide green OA when publishers do not allow it. Universities with Harvard-style rights-retention mandates will not provide OA when authors obtain waivers or when publishers require authors to obtain waivers as a condition of publication. 1. Nobody knows yet how green OA policies will affect journal subscriptions. For more than eight years, green OA mandates have applied to research in many fields outside physics. These mandates are natural experiments and we’re still monitoring their effects. At Congressional hearings in 2008 and 2010, legislators asked publishers directly whether green OA was triggering cancellations. In both cases, publishers pointed to decreased downloads but not to increased cancellations. 4. There is evidence that green OA decreases downloads from publishers’ web sites. When users know about OA and toll-access editions of the same article, many will prefer to click through to the OA edition, either because they aren’t affiliated with a subscribing institution or because authentication is a hassle. Moreover, when users find an OA edition, most stop looking. But decreased downloads are not the same thing as decreased or canceled subscriptions. Moreover, decreased downloads of toll-access editions from publisher web sites are not the same thing as decreased downloads overall. No one suggests that green OA leads to decreased overall downloads, that is, fewer readers and less reading. On the contrary, the same evidence suggesting that OA increases citation impact also suggests that it increases readers and reading. 6. Green OA mandates leave standing at least four library incentives to maintain their subscriptions to toll-access journals. Even the strongest no-loophole, no-waiver policies preserve incentives to maintain toll-access journal subscriptions. First, all funder OA mandates include an embargo period to protect publishers. For example, the OA mandates at the Research Councils UK allow an embargo of up to six months after publication. The NIH allows an embargo of up to twelve months. Libraries wanting to provide immediate access will still have an incentive to subscribe. Second, all funder OA mandates apply to the final version of the author’s peer-reviewed manuscript, not to the published version. If the journal provides copyediting after peer review, then the policies do not apply to the copyedited version, let alone to the formatted, paginated published edition. Libraries wanting to provide access to copyedited published editions will still have an incentive to subscribe. The purpose of these two policy provisions is precisely to protect publishers against cancellations. They are deliberate concessions to publishers, adopted voluntarily by funding agencies as compromises with the public interest in immediate OA to the best editions. When we put the two together, we see that funder-mandated OA copies of peer-reviewed manuscripts won’t compete with toll-access copies of the published editions for six to twelve months, and there will never be OA copies of the more desirable published editions unless publishers voluntarily allow them. Publishers retain life-of-copyright exclusivity on the published editions. Even if OA archiving does eventually erode subscriptions outside physics, publishers have longer and better protection from these effects than their lobbyists ever acknowledge. Third, funder OA mandates only apply to research articles, not to the many other kinds of content published in scholarly journals, such as letters, editorials, review articles, book reviews, announcements, news, conference information, and so on. Libraries wanting to provide access to these other kinds of content will still have an incentive to subscribe. Fourth, funder OA mandates only apply to articles arising from research funded by the mandating agency. Very few journals publish nothing but articles from a single funder, or even from a set of funders all of whom have OA mandates. Libraries wanting to provide access to all the research articles in a journal, regardless of the sources of funding, will still have an incentive to subscribe. This incentive will weaken as more and more funders adopt OA mandates, but we’re very far from universal funder mandates. As we get closer, unfunded research will still fall outside this category and the three other incentives above will still stand. The Association of College and Research Libraries addressed subscription incentives in a 2004 open letter on the NIH policy: “We wish to emphasize, above all, that academic libraries will not cancel journal subscriptions as a result of this plan. . . . Even if libraries wished to consider the availability of NIH-funded articles when making journal cancellation decisions, they would have no reasonable way of determining what articles in specific journals would become openly accessible after the embargo period.” In a 2006 study from the Publishing Research Consortium (PRC), Chris Beckett and Simon Inger asked 400 librarians about the relative weight of different factors in their decisions to cancel subscriptions. Other things being equal, the librarians preferred free content to priced content and short embargoes to longer ones. Publishers interpret this to mean that the rise of OA archiving will cause cancellations. The chief flaw with the study is its artificiality. For example, the survey did not ask about specific journals by name but only about resources with abstractly stipulated levels of quality. It also disregarded faculty input on cancellation decisions when all librarians acknowledge that faculty input is decisive. The result was a study of hypothetical preferences, not actual cancellation decisions. The three most important factors used to determine journals for cancellation, in declining order of importance, are that the faculty no longer require it . . . , usage and price. Next, availability of the content via open access (OA) archives and availability via aggregators were ranked equal fourth, but some way behind the first three factors. The journal’s impact factor and availability via delayed OA were ranked relatively unimportant. . . . With regard to OA archives, there was a great deal of support for the idea that they would not directly impact journal subscriptions. In short, toll-access journals have more to fear from their own price increases than from rising levels of green OA. Publishers who keep raising their prices aggravate the access problem for researchers and aggravate the sustainability problem for themselves. If the same publishers blame green OA and lobby against green OA policies, then they obstruct the solution for researchers and do very little to improve their own sustainability. 8. OA may increase submissions and subscriptions. Some subscription journals have found that OA after an embargo period, even a very short one like two months, actually increases submissions and subscriptions. For example, this was the experience of the American Society for Cell Biology and its journal, Some publishers fear that rising levels of green OA will not only trigger toll-access journal cancellations but also increase pressure to convert to gold OA. (Likewise, some OA activists hope for this outcome.) In fact, OA publishing might be more sustainable than TA publishing, as toll-access prices and the volume of research both grow faster than library budgets. (See section 2.1 on problems.) If publishers acknowledge that gold OA can be sustainable, and even profitable, and merely wish to avoid making lower margins than they make today, then their objection takes on a very different color. They’re not at risk of insolvency, just reduced profits, and they’re not asserting a need for self-protection, just an entitlement to current levels of profit. There’s no reason for public funding agencies acting in the public interest, or private funders acting for charitable purposes, to compromise their missions in order to satisfy that sense of publisher entitlement.

<question>:
What did the research show as the main reason for libraries canceling publication subscriptions?

<options>:
A The presence of extra media such as photos and commentary in the publication
B Whether or not the published content was completely free
C The length of content embargo that the subscription publisher used
D The cost and amount of use related to the subscription

<answer>:

D