Researchers from Spain, the UK, and the United States have successfull

Question

Researchers from Spain, the UK, and the United  States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers and finding a drug that can act on the binding of these proteins, and thereby possibly inhibit  growth of cancer cells.

A) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers and finding a drug that can act on the binding of these proteins, and thereby possibly inhibit

B) States, successfully unravelling the mechanism by which two proteins, MATα2 and MATβ, that join with each other, promoting the reproduction of tumor cells in liver and colon cancers, and have found a drug that can, by acting on the binding of these proteins, possibly inhibit

C) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other and promote the reproduction of tumor cells in liver and colon cancers, and have found a drug that can, by acting on the binding of these proteins, possibly inhibit

D) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers, and have found a drug that can act on the binding of these proteins, thereby possibly inhibiting

E) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other and therefore promote the reproduction of tumor cells in liver and colon cancers, have found a drug that can, by acting on the binding of these proteins, thereby possibly inhibit

thinkTheta · Accepted Answer

D.

Meaning difference between C and D.

C says "..have successfully unraveled the mechanism by which two proteins, MATα2 and MATβ, join with each other and promote the reproduction..", which essentially means they have unraveled two things - 1. mechanism by which two proteins join, and 2. mechanism by which two proteins promote the reproduction. According to the original paraphrase, they have only unraveled the mechanism by which two proteins join with each other. The modifier - promoting the reproduction..- modifies the previous action join.

adstudy · Answer

IMO D.

A) States  have successfully unravelled  the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers  and finding a drug  that can act on the binding of these proteins, and thereby possibly inhibit

Higlighted parts need to be parallel. Parallelism missed here. Hence Incorrect

B) States , successfully unravelling  the mechanism by which two proteins, MATα2 and MATβ, that join with each other, promoting the reproduction of tumor cells in liver and colon cancers,  and have found  a drug that can, by acting on the binding of these proteins, possibly inhibit

Higlighted parts need to be parallel. Parallelism missed here. Hence Incorrect

C) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other and promote the reproduction of tumor cells in liver and colon cancers, and have found a drug  that can, by acting on the binding of these proteins, possibly inhibit

Here option C says in highlighted part that the drug itself will help in inhibiting growth of cancer cells. But the meaning here should be that the drug acts on the binding of protein which in turn helps in inhibiting growth of cancer cells.  Hence Incorrect

D) States  have successfully unravelled  the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers,  and have found a drug  that  can act on the binding of these proteins, thereby possibly inhibiting

Parallelism and meaning both maintained here.  Hence Correct.

E) States  have successfully unravelled  the mechanism by which two proteins, MATα2 and MATβ, join with each other and therefore promote the reproduction of tumor cells in liver and colon cancers, have found a drug that can, by acting on the binding of these proteins, thereby possibly inhibit
 
Parallelism required here but removed.  Hence Incorrect

misshelllobo · Answer

I chose D too.

Narrowed it down to C and D and then chose D because I found D clearer.
Thought this part in C - "have found a drug that can, by acting on the binding of these proteins, possibly inhibit" was less direct and needlessly breaks the flow of the part that says - have found a drug that can possibly inhibit.

JDF · Answer

I disagree with the OA. D reads as if the scientists “unraveled..., prompting..., and have found...”. It falsely ascribes the promoting to the scientists instead of the proteins and isn’t parallel when it does so.

C doesn’t have this problem. It actually remains unclear to me what the grammatical error in C is.

Posted from my mobile device

C doesn’t have this problem. It actually remains unclear to me what the grammatical error in C is.

Posted from my mobile device

goaltop30mba · Answer

what is the ideal time for this question..???

took about 3 mins to get down to D.

Great question !!

generis · Answer

If you are having trouble understanding what this sentence should express, strip it. -- Remove modifiers, including prepositional phrases, adverbs, and even appositive phrases (in this case, the names of the proteins). -- Put square brackets around words that must stay but that appear to be errors. Researchers from Spain, the UK, and the United States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ , join with each other, the reproduction of tumor cells in liver and colon cancers and a drug that can act on the binding of these proteins, and thereby possibly inhibit growth of cancer cells. Researchers ... have unraveled the mechanism by which two proteins ... join with each other, promoting the reproduction of tumor cells ... and a drug that can possibly inhibit growth of cancer cells. Now we can tease out the meaning issues. Researchers have unraveled X and have found Y. X = the mechanism by which two proteins join with each other and thereby promote reproduction of tumor cells Y = a drug that can affect the binding of the proteins and thus possibly inhibit the growth of cancer cells Problems with option A that we need to correct to get the meaning straight. -- First, researchers, not the joined proteins, found the drug. The verbs attached to "researchers" must be parallel. -- Second, "promoting the reproduction of tumor cells" results from the joinder of the two proteins, so the participial modifier (the verbING) works. Among other functions, such modifiers present the result of the previous clause. Be on guard, then, that causation is clear in the options. Researchers have -- UNRAVELLED ------ the mechanism ----------- by which two proteins join with each other ------------and thus promote the reproduction of tumor cells and -- FOUND ----- a drug -----------that can possibly inhibit growth of cancer cells. • Split #1: Verbs must be parallel Option A pairs have unraveled and finding . Not parallel. Option B pairs unraveling and have found . Not parallel. Eliminate A and B Split #2: Two independent clauses cannot be joined with a comma alone Researchers have unraveled X and have found Y In Option E the verb tenses are parallel, but option E needs an AND to introduce the second independent clause. Two independent clauses cannot be joined by a comma alone. Option E is a "comma splice." Eliminate E • Split #3 - Style: avoid splitting verbs with long phrases; causality Stylistically, D is far superior to C. The verbs have already been split by the adverb possibly . The long prepositional phrase set off by commas in passive voice that lies between can and inhibit in option C is not as rhetorically effective as the that-clause without commas in option D. C) ... a drug that can, by acting on the binding of these proteins, possibly inhibit D) ... a drug that can act on the binding of these proteins, thereby possibly inhibiting Occasionally, we separate a helping verb from a main verb, an action called "splitting the verb." The word "possibly" splits can from inhibit in both C and D. We "split the verb" for emphasis or clarity. Emphatic, correct: You can easily see bright orange vests in a forest. -- Awkward: You easily can see bright orange vests in a forest.

-- Probably incorrect, certainly awkward: You can see easily bright orange vests in a forest.

-- Just average, correct: You can see bright orange vests in a forest easily

Option C, though, does not deploy a short adverb or a short phrase between can and inhibit . Further, its long prepositional phrase must be set off by commas in a sentence already full of commas. Option D does not split the verbs any further and does not interrupt the flow of the sentence. Finally, D expresses causality better than C does. C uses "and promote" to convey the result of the joined proteins. Option D uses "promoting" to convey that result. As a means to convey causality, GMAC dislikes the word and. Eliminate C Answer D

generis · Answer

Hi  JDF  , welcome to gmatclub.

You are correct. Option C is grammatical. Stylistically, though, it is inferior to (D).

Your syntax suggests that you are a native speaker.
Warning: this sentence will hurt your ears.

I can see how you might think it were the case that D connects  promoting  to  researchers ,
but the participial modifier actually severs that connection. 
That is, the function of this participial modifier precludes a connection between  promoting  and  researchers .

Promoting  presents the result of the preceding which-clause and "wraps up" that clause.
Generally, COMMA + present participle modifies the immediately preceding clause, subject of that clause, or noun before the comma.
 Promoting  modifies what the proteins do, not what researchers did.

Further, by presenting a clear result word,  promoting  helps us segue more smoothly back to the main subject of the sentence, researchers, and the second thing they did.

I agree that option C sounds cleaner in this part: 
. . . two proteins . . .  join  with each other and  promote  the reproduction . . .

"Sounds cleaner" does not solve two problems:
(1) GMAC really dislikes AND to convey causality or result. 
If (C) were to say . . . join with each other and THUS promote. . .,
causation would be clear. By contrast, the function of the participial modifier in D in this instance is to convey result.

(2) the prepositional phrase that modifies  drug  in option C is a hot mess. See my post above.
 
Option D, stripped, to check on causality:
Researchers   from Spain, the UK, and the United States   have successfully unravelled the mechanism by which two proteins,   MATα2 and MATβ ,  join with each other, promoting the reproduction of tumor cells   in liver and colon cancers  , and have found a drug that can act on the binding of these proteins, thereby possibly inhibiting growth of cancer cells.

Researchers have successfully unraveled the mechanism by which two proteins join with each other, promoting the reproduction of tumor cells, and have found a drug that can act on the binding of these proteins, thereby possibly inhibiting growth of cancer cells.

Causation is clear. 
Is this sentence awkward? Yes. 
Writing these sentences is incredibly difficult.
As an editor, at minimum I would change this single sentence into two sentences.

We are looking for the best of five options, though, not a perfect option.
GMAC people prefer crystal clear causation such as that in D. 
They dislike unnecessarily interrupted flow such as that produced by the prepositional modifier in option C.

GMAT sentence correction strategy is a game all its own.

Hope that analysis helps.

JDF · Answer

Thanks for the reply. I think I do remember something from the Manhattan materials about not using “and” to show causation. Hopefully I’ll remember it next time.

Posted from my mobile device

bnairsurya · Answer

Option C tweaks the meaning.... 
It feels like the scientists found out the cure by acting on the binding of the proteins. Even though that might be the case, but still D provides a clear meaning too

Hahshsh · Answer

I read other posts but I still cant find a concrete reason to eliminate option c. Got very confused between c and d

krrishwins · Answer

GMATNinja

I chose D over C.

"States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other and promote the reproduction of tumor cells in liver and colon cancers, and have found a drug that can, by acting on the binding of these proteins, possibly inhibit"

Eventhough i considered all the reason stated here, in addition to that i also considered a Verb "Inhibit". Ideally it should be Singular right? 
Since in the option D this verb was not there i chose D over C. I want to double check whether i am right on my understanding?

Regards,
Gopalakrishnan

Crytiocanalyst · Answer

Researchers from Spain, the UK, and the United  States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers and finding a drug that can act on the binding of these proteins, and thereby possibly inhibit  growth of cancer cells./quote]

A) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers and finding a drug that can act on the binding of these proteins, and thereby possibly inhibit
The parallelism and meaning isn't maintained therefore out

B) States, successfully unravelling the mechanism by which two proteins, MATα2 and MATβ, that join with each other, promoting the reproduction of tumor cells in liver and colon cancers, and have found a drug that can, by acting on the binding of these proteins, possibly inhibit
The meaning and parallelism isn't maintained therefore out

C) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other and promote the reproduction of tumor cells in liver and colon cancers, and have found a drug that can, by acting on the binding of these proteins, possibly inhibit
D better conveys the meaning therefore out

D) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other, promoting the reproduction of tumor cells in liver and colon cancers, and have found a drug that can act on the binding of these proteins, thereby possibly inhibiting
The meaning is perfect maintaining parallelism therefore let us hang on to it

E) States have successfully unravelled the mechanism by which two proteins, MATα2 and MATβ, join with each other and therefore promote the reproduction of tumor cells in liver and colon cancers, have found a drug that can, by acting on the binding of these proteins, thereby possibly inhibit[
The meaning isn't perfect along with parallelism therefore out

Therefore IMO D

Researchers from Spain, the UK, and the United States have successfull

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Researchers from Spain, the UK, and the United States have successfull

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