GMAT Critical Reasoning (CR) | Re: Exposure to certain chemicals commonly used in elementary

Premise: Exposure to certain chemicals commonly used in elementary schools as cleaners or pesticides causes allergic reactions in some children.
Premise: Elementary school nurses in Renston report that the proportion of schoolchildren sent to them for treatment of allergic reactions to those chemicals has increased significantly over the past ten years.

Conclusion: Therefore, either Renston’s schoolchildren have been exposed to greater quantities of the chemicals, or they are more sensitive
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