In my opinion,

issues with Choice B.

that taking vitamin E.....increases the risk....looks awkward
shift from "may actually increase" to "actually increases"!!!!

If we go by parallelism (considering active voice) B and C are ruled out. GMAT gives a lot emphasis on parallelism so it should be the first thing to consider while doing the process of elimination. May be MGMAT staff would throw some more light here.....

reveal not only X but also Y - this is E

not only (Verb)reveal X but also (Missing verb) Y -- THis is C

If we look at the structure of the sent . we do understand that changes in the composition does the revealing activity of both X and Y

Hi, I hope I am posting in the right section. Please let me know if I am wrong on this part. I will take corrective actions necessary (If needed ) from my side. I want to make sure that I get MGMAT's response on my post below as I seriously need some advice. In my prep of Verbal I mainly concentrate...