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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?


Option A:

A zoo employee who develops a serious animal-induced allergy is very likely to switch to some other occupation.

Option B:

A zoo employee is more likely than a person in the general population to keep one or more animal pets at home

Option C:

The percentage of the general population whose level of exposure to animals matches that of a zoo employee is quite small.

Option 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.

Option E:

Zoo employees seldom wear protective gear when they handle animals in their care.

Difficulty Level



Option A is the correct answer.

Option Analysis

Question type: Strengthen the Conclusion 

Summary of the argument: Since 30% of people working in the zoo have animal-induced allergies, the argument concludes that more than 30% of the general population will have animal-induced allergies.  


A) Correct Answer 

B) The likelihood of a person possessing a pet doesn’t really talk about the percentage of people having animal-induced injuries.  

C) This doesn’t contribute to the logic of why 30% have animal-induced injuries.  

D) We don’t know this.  

E) This doesn’t contribute to the logic of the argument saying 30% of people have animal-induced injuries.