GMAT Critical Reasoning (CR) | Re: Mental Health CR

D is the answer.

if you guys have read POWERSCORE CR bible then you are going to understand what i am writing below.

this type of assumption questions areDEFENDER type. in these type of questions the answer choice will try to defend the argument conclusion.

the conclusion here in the argument is:

The researcher concluded from this experiment that the immune system protects against mental illness as well as against
physical disease.

or in short

immune system -->> protects against
...

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