Critical Reasoning

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.
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.

OA: A

richachampion wrote: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.
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.

Conclusion: Percentage of people in general population with animal-induced allergies is greater than 30%.

Premise: At zoo, 30% of workers had animal-induced allergies.

We want to strengthen the conclusion here. So why might the percentage of people in the general population suffering from animal-induced allergies be higher than the percentage of zoo employees suffering from animal-induced allergies? Imagine you work at a zoo and every time you're in the vicinity of a lion, your face puffs up and your body itches. You might find another line of work, right?
Say that 8 of 15 employees at the zoo had an allergic reaction to some animal. 5 decide that it isn't worth it. Now we're left with 3 of 10 employees, or 30% suffering from the allergy. This is what A gives us.
(Now imagine that 8 of 15 people in the general population suffer from an animal-induced allergy. They're probably not going to give up their pets. Thus, we end up with more than 50% of people in the general population suffering from animal-induced allergies.)

I posted explanation here:
https://www.beatthegmat.com/people-who-h ... 85101.html