A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.
The researcher’s conclusion depends on which of the following assumptions?

Question

Examsnet · Accepted Answer

Correct Answer is :  Mental illness does not cause people’s immune-system activity to decrease.

GMAT Verbal Reasoning Practice Test 4