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

<passage>:
Will a general shift to OA leave casualties? 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. This chapter, then, focuses on the strongest green OA mandates at funding agencies, like the Wellcome Trust and NIH, which allow no opt-outs for publishers or grantees. Will strong green OA policies of that kind trigger cancellations of toll-access journals? Here are 10 parts of any complete answer. 1. Nobody knows yet how green OA policies will affect journal subscriptions. Rising levels of green OA may trigger toll-access journal cancellations, or they may not. So far they haven’t. Physics has the highest levels and longest history of green OA. The evidence from physics to date is that high levels of green OA don’t cause journal cancellations. On the contrary, the relationship between arXiv (the OA repository for physics) and toll-access physics journals is more symbiotic than antagonistic. It would definitely help to understand why the experience in physics has gone as it has and how far it might predict the experience in other fields. But so far it’s fair to say that we don’t know all the variables and that publishers who oppose green OA mandates are not among those showing a serious interest in them. When publisher lobbyists argue that high-volume green OA will undermine toll-access journal subscriptions, they don’t offer evidence, don’t acknowledge the countervailing evidence from physics, don’t rebut the evidence from physics, and don’t qualify their own conclusions in light of it. They would act more like scientific publishers if they acknowledged the evidence from physics and then argued, as well as they could, either that the experience in physics will change or that fields other than physics will have a different experience. 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. 5. Most publishers voluntarily permit green OA. Supplementing the natural experiments of green OA mandates are the natural experiments of publishers who voluntarily permit green OA. The Nature Publishing Group is more conservative than most toll-access publishers by requiring a six-month embargo on green OA, but more progressive than most by positively encouraging green OA. NPG reported the latest results of its multidisciplinary natural experiment in January 2011: “We have, to date, found author self-archiving compatible with subscription business models, and so we have been actively encouraging self-archiving since 2005.” This or something similar to it must be the experience of the majority of toll-access publishers who voluntarily permit green OA. Even if they don’t actively encourage green OA, most permit it without embargo. If they found that it triggered cancellations, they would stop. 6. Green OA mandates leave standing at least four library incentives to maintain their subscriptions to toll-access journals. 7. Some studies bear on the question of whether increased OA archiving will increase journal cancellations. 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, 9. Some publishers fear that green OA will increase pressure to convert to gold OA. 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.) 10. Green OA policies are justified even if they do create risks for toll-access journals. If we’re only interested in the effect of rising levels of green OA on toll-access publishers, then we can stop at points 1–9. But if we’re interested in good policy, then we must add one more factor: Even if green OA does eventually threaten toll-access journal subscriptions, green OA policies are still justified. I won’t elaborate this point here, since it takes us beyond the topic of casualties to the full case for OA, which is spread throughout the rest of the book. But here’s one way to put the debate in perspective: There are good reasons to want to know whether rising levels of green OA will trigger cancellations of toll-access journals, and perhaps even to modify our policies in light of what we learn. But there are no good reasons to put the thriving of incumbent toll-access journals and publishers ahead of the thriving of research itself.

<question>:
Which answer doesn't support the idea that green OA isn't likely to cause subscription cancellations?

<options>:
A 6
B 4
C 2
D 10

<answer>:

D