It is mentioned in the last part of the post; if the claim says X is causing Y, then the option which rules out reverse causation and says Y does not cause X will strengthen the claim.
On the GMAT, if the assumption is not true then the conclusion has to fail. So a good test is to negate the option and see if the assumption still holds; if we negate B it becomes, mental illness is NOT similar to physical disease in its effects on body systems, this does not in any way lead to the conclusion that immune system protects against mental illness to fail.
Just to re-iterate, if there is a correlation that X and Y are highly correlated then it might be possible that X is causing Y or Y is causing X; in choosing one of the two, the assumption is that the other is not true.
The question is taken from the Critical Reasoning (#7) section of the GMAT Verbal Review.
Thanks a lot for these strengthen, weaken posts. My accuracy in such questions, especially the weaken ones have taken a quantum leap thanks to these minor clarifications. In CAT I still get confused a bit in FIJ [Fact Inference Judgement] questions. Will you be posting on this topic as well ?
CAT-holics 
sir what will be the correct answer option if the question was strengthen the claim????
It is mentioned in the last part of the post; if the claim says X is causing Y, then the option which rules out reverse causation and says Y does not cause X will strengthen the claim.
‘B’ seems to be the right answer option
On the GMAT, if the assumption is not true then the conclusion has to fail. So a good test is to negate the option and see if the assumption still holds; if we negate B it becomes, mental illness is NOT similar to physical disease in its effects on body systems, this does not in any way lead to the conclusion that immune system protects against mental illness to fail.
Just to re-iterate, if there is a correlation that X and Y are highly correlated then it might be possible that X is causing Y or Y is causing X; in choosing one of the two, the assumption is that the other is not true.
The question is taken from the Critical Reasoning (#7) section of the GMAT Verbal Review.
Thanks a lot for these strengthen, weaken posts. My accuracy in such questions, especially the weaken ones have taken a quantum leap thanks to these minor clarifications. In CAT I still get confused a bit in FIJ [Fact Inference Judgement] questions. Will you be posting on this topic as well ?
Hey good to know the post was helpful.
Will do a post on FIJ after we finish the rest of the Critical Reasoning Question Types.
Regards,
T
Hi T,
Is the post on FIJ up?
and also on questions like – “which of these is a strong/ weak argument’