| A survey of alumni of the class of 1960 at Aurora University yielded puzzling results. When asked to indicate their academic rank, half of the respondents reported that they were in the top quarter of the graduating class in 1960. Which one of the following most helps account for the apparent contradiction above? (A) A disproportionately large number of high-ranking alumni responded to the survey. (B) Few, if any, respondents were mistaken about their class rank. (C) Not all the alumni who were actually in the top quarter responded to the survey. (D) Almost all of the alumni who graduated in 1960 responded to the survey. (E) Academic rank at Aurora University was based on a number of considerations in addition to average grades.
答案是a,我觉得e也说得通呀，标准不同，在每个标准下可能会有不同的 top quarter of the graduating class吧？ 不知道我理解的对不对，请大家指点~~ | 
