according to survey of graduating Source Gmat prep

rommysingh wrote:According to a survey of graduating medical students conducted by the Association of American Medical Colleges, minority graduates are nearly four times more likely than are other graduates in planning to practice in socioeconomically deprived areas.

Getting this one right is definitely not a simple matter of finding glaring issues such as maybe a misplaced modifier and a problem with noun verb agreement. You more have to find the various somewhat subtle issues that exist in all of the answer choices but one.

(A) minority graduates are nearly four times more likely than are other graduates in planning to practice

One issue here is the expression likely...in, which is unidiomatic. The idiomatic way to use likely is likely to.

(B) minority graduates are nearly four times more likely than other graduates who plan on practicing

This one has in the comparison an issue created by the addition of who. Because who plan on practicing... is merely a modifier, with this answer choice the sentence says basically that minority graduates are nearly four times more likely than other graduates. That's all. Likely to what? It doesn't really say.

(C) minority graduates are nearly four times as likely as other graduates to plan on practicing

This one looks good. We have the correct form, likely...to, and the comparison works.

(D) it is nearly four times more likely that minority graduates rather than other graduates will plan to practice

The most obvious issue with this one is the misuse of rather. The minority graduates are being compared to the other graduates and rather does not express comparison but rather replacement. Another issue is the addition of will, which seems redundant. The idea is not that they will plan what they will do. They are just planning to do something.

(E) it is nearly four times as likely for minority graduates than other graduates to plan to practice

In this one the comparison is all mixed up and nonsensical. What does it is four times as likely for minority graduates than other graduates even mean?

So C is the best.

Option A is incorrect because "likely" is not followed by "to verb". This word is always followed by a "to verb".In this choice what we have is "likely... in planning to practice". This is the incorrect idiom here. Option B is also incorrect for the same reason. In fact, the "who clause" just provided additional information. The whole planning part now belongs to the "other graduates" and do not even relate to "minority graduates" in the main clause.Option C rectifies the idiom error in Choice A. Hence (c).