请大牛指点一下，好像A根本不搭啊！

斯巴达

People who have spent a lot of time in contact with animals often develop animal-induced allergies, some of them quite serious. In a survey of current employees in major zoos, about 30 percent had animal-induced allergies. Based on this sample, experts conclude that among members of the general population who have spent a similarly large amount of time in close contact with animals, the percentage with animal-induced allergies is not 30 percent but substantially more.
Which of the following, if true, provides the strongest grounds for the experts’ conclusion?

A.    A zoo employee who develops a serious animal-induced allergy is very likely to switch to some other occupation.  （不理解这话意思，转换到其它职业，啥意思）
B.    A zoo employee is more likely than a person in the general population to keep one or more animal pets at home
C.    The percentage of the general population whose level of exposure to animals matches that of a zoo employee is quite small.
D.    Exposure to domestic pets is, on the whole, less likely to cause animal-induced allergy than exposure to many of the animals kept in zoos.
E.    Zoo employees seldom wear protective gear when they handle animals in their care.

Queeny11

原文说 总和动物接触会得一种病， 调查出动物园里 得病的有30% 结论是 总体来说得病的应该超过30%~~~~也就是肯定有得病的现在不在动物园里工作的啦。。
A说的就是这个意思。、

斯巴达

switch的意思是啥啊，我理解是动物员员工跳槽呢

爆炒拖鞋

先说结论：砖家们结论是和动物呆的越久。染病的几率远比平均的30%高。
但是为什么之前测算的是30%捏？

因为A。染病的跳槽走了。。。就降低了总几率。