紧急的求助一道CR 寂静题，谢谢大家了！

Every fall Croton's jays migrate south.  The jays always join flocks of migrating crookbeaks with which they share the same summer and winter territories.  If a jay becomes separated from the crookbeaks it is accompanying, it wanders until it comes across another flock of crookbeaks.  Clearly, therefore, Croton's jays lack the navigational ability to find their way south on their own.

Which of the following, if true, most strengthens the argument above?

A. Croton's jays lay their eggs in the nests of crookbeaks, which breed upon completing their southern migration.

B. The three species most closely related to crookbeaks do not migrate at all.

C. In the spring, Croton's jays migrate north in the company of Tattersall warblers.

D. Species other than Croton's jays occasionally accompany flocks of migrating crookbeaks.

E. In the spring, crookbeaks migrate north before Croton's jays do.
这道题选什么呢？我选了C，答案我又看到是A，怎么解释？还是答案错了？

Industrial accidents are more common when some of the people in safety-sensitive jobs have drinking problems than when none do.  Since, even after treatment, people who have had drinking problems are somewhat more likely than other people to have drinking problems in the future, any employer trying to reduce the risk of accidents should bar anyone who has ever been treated for a drinking problem from holding a safety-sensitive job.

Which of the following, if true, most seriously undermines the argument above?

A.    Some companies place employees who are being treated for drinking problems in residential programs and allow them several weeks of paid sick leave.
B.    Many accidents in the workplace are the result of errors by employees who do not hold safety-sensitive jobs.
C.    Workers who would permanently lose their jobs if they sought treatment for a drinking problem try instead to conceal their problem and continue working for as long as possible.
D.    eople who hold safety-sensitive jobs are subject to stresses that can exacerbate any personal problems they may have, including drinking problems.
E.    Some industrial accidents are caused by equipment failure rather than by employee error.
这道题的答案是什么呢？我选的是C
谢谢NN