Pronoun antecedent

[hitzs]

1. In large doses, analgesics that work in the brain as antagonists to certain chemicals have caused psychological disturbances in patients, which may limit their potential to relieve severe pain.
(A) which may limit their potential to relieve
(B) which may limit their potential for relieving
(C) which may limit such analgesics’ potential to relieve
(D) an effect that may limit their potential to relieve
(E) an effect that may limit the potential of such analgesics for relieving

I have a question on this problem, I was able to get till D & E and then picked D thinking that 'their' refers to analgesics because as told by Bob, pronoun refers to subject of previous clause, which is "analgesics" . Also E looks to me lengthy
por favor, el señor advise where i'm going wrong...thanx!!

[a_sin]

which referes to the nearest pronoun.. in this case it is not clear whether theirs refers to patients or analgesics..

So I would go with -- C - again which introduces a phrase.. Let me know the Official Answer answer

[800Bob]

I say E.

This is an interesting item. I'm not sure it's a real GMAT item, but I still think it's a useful one for illustrating the dangers of following a rule of grammar too literally. Those of us with extremely analytical minds would like to think that the rules of grammar can be expressed with precision. We must face the fact, however, that language is not strictly logical.

I stand by the guideline that a pronoun will tend to refer to the subject of the preceding phrase if the pronoun and subject agree in number. (We have seen many, many examples where the pronoun does not automatically refer to the nearest noun.) So in this case it would seem that "their" in choice D refers grammatically and logically to "analgesics." The problem with D, however, is that there are just too many other plural nouns between "analgesics" and "their": "antagonists," "chemicals," "disturbances," "patients." For this reason it is better to write "of such analgesics" than "their."

Here's what I tell my students: If you have a choice that uses a pronoun and a choice repeats the noun, generally you should go for the one that repeats the noun. A little repetition for the sake of clarity is not a bad thing.

[amitg_ind]

I Pick E as the correct idiom is 'potential for' and hence its between B and E. next 'which' usage is wrong in B hence E.

[geekybiz1]

E is my pick too.

[rits700]

one more vote for E - the only option which has the clarity in meaning.

[shud]

I would go for a safe approach ie E.
But GMAt might consider D a correct option and E as wordy (redundant words).

[zombie_in]

E is clear..

[suchikumar]

Thanks Bob.. your explanations teaches us rather than just giving us solutions. Thanks a ton

[x97agarwal]

IMO E.

the use of which in all choices is a modifier issue.

D. their is ambiguous

E is the right answer