In 2005, an environmental group conducted a study measuring the levels of toxic chemicals in the bodies of eleven vol...

on October 29 at 04:30PM

Hello @3tromero,

The author makes two contradictory statements.
1. Scientifically valid inferences could not be drawn from the study because of the small sample size.
2. The study proves that the regulation banning PCBs was effective.

Do you see the problem here? The author explains how the sample size is too small to make a valid inference, and then proceeds to make an inference anyway.

The word "proves" is an indicator that this conclusion is far too strong to have come from an incomplete study. This is the inconsistency that is referred to in answer choice A.