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

<passage>:
I'm afraid we'll never know the answer to that exact question, since I'm not brave enough to expose my own taste to a real test. But I'm brave enough to expose my friends'. This summer, while working at Microsoft, I put out a call for volunteers for a "science of beer" experiment. Testing candidates had to meet two criteria: 1) they had to like beer and 2) they had to think they knew the difference between mass products and high-end microbrews. Twelve tasters were selected, mainly on the basis of essays detailing their background with beer. A few were selected because they had been bosses in the Microsoft department where I worked. All were software managers or developers all were male, but I repeat myself. Nearly half had grown up outside the United States or lived abroad for enough years to speak haughtily about American macrobrews. Most tasters came in talking big about the refinement of their palates. When they entered the laboratory (which mere moments before had been a Microsoft conference room), they discovered an experiment set up on the following lines: 1 Philosophy                : The experiment was designed to take place in two separate sessions. The first session, whose results are revealed here, involved beers exclusively from the lager group. Lagers are the light-colored, relatively lightly flavored brews that make up most of the vattage of beer consumption in the United States. Imported lagers include Foster's, Corona, and Heineken. Budweiser is a lager so are Coors, Miller, most light beers, and most bargain-basement beers. Beer snobs sneer at lagers, because they look so watery and because so many bad beers are in the group. But the lager test came first, for two reasons. One, lagers pose the only honest test of the ability to tell expensive from dirt-cheap beers. There are very few inexpensive nut brown ales, India pale ales, extra special bitters, or other fancy-pantsy, microbrew-style, nonlager drinks. So if you want to see whether people can taste a money difference among beers of the same type, you've got to go lager. Two, the ideal of public service requires lager coverage. This is what most people drink, so new findings about lager quality could do the greatest good for the greatest number. In the second stage of the experiment, held several weeks later, the same testers reassembled to try the fancier beers. The results of that tasting will be reported separately, once Microsoft's mighty Windows 2000-powered central computers have . 2 Materials                : Ten lagers were selected for testing, representing three distinct price-and-quality groups. Through the magic of the market, it turns out that lager prices nearly all fall into one of three ranges: b) Middle at around 80 cents per pint, or under $4 per six pack. c) Low at 50 cents to 55 cents per pint, or under $3 per six pack. The neat 6:3:2 mathematical relationship among the price groups should be noted. The high-end beers cost roughly three times as much as the cheapest ones, and twice as much as the middle range. The beers used in the experiment were as follows: also, they were just going back to software coding when they were done.) Saltines were available to cleanse the palate. The cups were red opaque plastic, so tasters could judge the beer's color only from above. There was no time limit for the tasting, apart from the two-hour limit in which we had reserved the conference room. One experimenter (the boss of most of the others there) rushed through his rankings in 10 minutes and gave the lowest overall scores. The taster who took the longest, nearly the full two hours, had the ratings that came closest to the relative price of the beers. (This man grew up in Russia.) The experimenters were asked not to compare impressions until the test was over. After tasting the beers, each taster rated beers A through J on the following standards: Overall quality points: Zero to 100, zero as undrinkable and 100 as dream beer. Purely subjective measure of how well each taster liked each beer. Price category: The tasters knew that each beer came from the expensive, medium, or cheap category--and they had to guess where A through J belonged. A rating of 3 was most expensive, 2 for average, 1 for cheap. Description: "Amusing presumption," "fresh on the palate," "crap," etc. Best and Worst: Tasters chose one Best and one Worst from the "flight" (as they would call it if this were a wine test). When the session was over, results for each beer were collected in a grid like this: To see all the grids for all the beers, click . Bottom rankings were also clear. Of the 11 naming a Worst beer, five chose Grolsch , the most expensive beer in the survey. Results by best/worst preference: 2. Overall                 preference points                . This was a subtler and more illuminating look at similar trends. The beers were ranked on "corrected average preference points"--an average of the zero-to-100 points assigned by each taster, corrected, just like ice skating scores, by throwing out the highest and lowest score each beer received. The tasters used widely varying scales--one confining all beers to the range between zero and 30, another giving 67 as his lowest mark. But the power of our corrected ranking system surmounted such difficulties to provide these results: Here again one costly beer-- Sam Adams --shows up well, while another, Grolsch , continues to struggle, but not as badly as the medium-price Miller Genuine Draft . Sam's success could reflect its quasi-mislabeling, presenting a strong-flavored beer as a "lager." It could also reflect that participants simply thought it was good. (Only one guessed it was Sam Adams.) As for Grolsch ... it is very strongly hopped, which can seem exotic if you know you're drinking a pricey import but simply bad if you don't. MGD overtook Grolsch in the race for the bottom because, while many people hated Grolsch, some actually liked it another, "Water. LITE." But the magic of statistics lets us see the larger trends. 5 Conclusions                . Further study is needed. But on the basis of evidence to date, we can say: One and only one beer truly survived the blind taste test. This is Sam Adams , which 10 tasters independently ranked "best" without knowing they were drinking a fancy beer. (They knew it was darker than the others but couldn't have known whether this was some trick off-brand sneaked into the test.) Don't serve Grolsch unless you know people will consider it exotic, or unless you've invited me. Apart from Sam Adams and Grolsch, the tasters really had trouble telling one beer from another . This conclusion is implicit in many of the findings, but it was really obvious during the experiment itself, when the confident look of men-who-know-their-beer quickly turned to dismay and panic as they realized that all the lagers tasted pretty much the same. The evidence suggests other implications about specific beers. For instance, the comments about Coors Light are much less enthusiastic than the average-or-better numerical rankings. Most tasters paused to complain about it--"fizzy and soapy"--before giving it reasonable marks. But the main implication, and the most useful consumer news from this study, is a radically simplified buying philosophy for lager beers. Based on this study, rational consumers should: 1) Buy Sam Adams when they want an individual glass of lager to be as good as it can be.

<question>:
How did the author feel about their ability to detect differences between the test groups over the course of the study?

<options>:
A At first they didn’t have confidence they could tell them apart
B They wanted to participate in the tasting, but after they saw how difficult is was for the rest of the participants they withdrew
C They couldn’t understand why the other tasters were struggling because it was so easy
D They thought they had a good chance at choosing the correct beer for each sample, but when they got into tasting their confidence faded

<answer>:

A