FEDERAL RESERVE SYSTEMMM HOPE THIS HELPSS
A n environmental stressor could be;
the weather, too hot, say a heatwave, which can cause heat stroke, dehydration etc, or too cold, where vulnerable people may freeze to death, or develop frost bite etc.
So, some characteristic part of where we live which may, under certain conditions cause difficulty for us or some other living being.
I would say it may be a dermatologist
The correct answer is letter A. Pre-existing conditions are usually the exclusions of health care programs available in most societies. This is the reason why there are a lot of lawsuits filed against healthcare companies who do not fairly adhere with the interests of their clients/patients.