Sentence Correction

In his research paper, Dr. Frosh, medical director of the Payne Whitney Clinic, distinguishes mood swings. which may be violent without their being grounded in mental disease, from genuine manic-depressive psychosis.

(A)mood swings, which may be violent without their being grounded in mental disease, from genuine manic-depressive psychosis
(B)mood swings, perhaps violent without being grounded in mental disease, and genuine manic-depressive psychosis ,
(C)between mood swings, which may be violent without being grounded in mental disease, and genuine manic-depressive psychosis
(D)between mood swings, perhaps violent without being grounded in mental disease, from genuine manic-depressive psychosis
(E)genuine manic-depressive psychosis and mood swings, which may be violent without being grounded in mental disease

What sort of problem(s)in the options B and D?

Would any one explain "perhaps violent..." part as modifier?

Thanks.

IMO-C
its just idiom based distinguish between x and y. rest all are breaking the idiom.

Yup, this one comes down to Idiom. The answer is C.

We've got two Idioms to choose from:

Distinguishes between X and Y.

or

Distinguishes X from Y.

You're correct that "perhaps violent..." would be a modifying clause, but B breaks the Idiom because there is no "between" but they are using the word "and".

D is incorrect because it also breaks the Idiom. It uses "between" and then tries to pair it with "from" which is wrong. We can use "between...and" OR "from" but you cannot mix and match.

Thanks for the reply. I know the idiom "between X and Y", where X and Y must be grammatically parallel. I wanted to know what sort of problem(s)in B and D has/have been made by "perhaps violent..." part?

Thanks.

The "perhaps violent..." part is okay. It could potentially be correct if the Idiom itself wasn't wrong.

Distinguishes X from Y. - how about A ?

distinguishes mood swings from genuine manic-depressive psychosis.

Thanks.

A is much more awkward than C. "Their" is unnecessary - the sentence would make more sense without it.

By the way, just searched and found two other discussions on this questions if you're interested:

https://www.beatthegmat.com/when-can-we- ... 15407.html

https://www.beatthegmat.com/distunguish- ... 15177.html

#vivian,

Thanks for those links.