lsat1-1-13 and lsat1-1-20

13. Top college graduates are having more difficulty demonstrating their superiority to prospective employers than did the top students of twenty years ago when an honors degree was distinction enough. Today’s employers are less impressed with the honors degree. Twenty years ago no more than 10 percent of a given class graduated with honors. Today, however, because of grade inflation, the honors degree goes to more than 50 percent of a graduating class, Therefore, to restore confidence in the degrees they award, colleges must take steps to control grade inflation.

Which one of the following is an assumption that, if true, would support the conclusion in the passage?

(A) Today’s students are not higher achievers than the students of twenty years ago.

(B) Awarding too many honors degrees causes colleges to inflate grades.

(C) Today’s employers rely on honors ranking in making their hiring decisions.

(D) It is not easy for students with low grades to obtain jobs.

(E) Colleges must make employers aware of the criteria used to determine who receives an honors degree.

现在的“牛人”比以前的“牛人”更难以向顾主证明其卓越，因为过去的“牛人”凭“牛人”的等级就可以了，而现在的顾主对“牛人”的等级不太感冒了。原因是现在的学生中得到“牛人”等级的很多，所以学校一定要把得到“牛人”等级的人数控制一下。如果，现在的学生果然优秀，那么更多的人得到“牛人”就是应该的，而文中认为不应该给这么多“牛人”，那假设一定是，本来不应该有这么多牛人的，所以A是假设。

a一定是假设吗???再牛人中选更牛的不行吗?答案好象跟前半段没什么关系啊??

还有lsat1-1-20好象没讨论啊?