Sentence Correction

In terms of physics, the characteristic feature of the roller coaster is that the cars' potential energy, gained through their being lifted by a chain drive through the Earth's gravity to the top of the first drop, has been converted to kinetic energy by the time the ride ends.

(A) cars' potential energy, gained through their being lifted by a chain drive
(B) cars' potential energy, a gain achieved as they are lifted by a chain drive
(C) potential energy from the cars' being lifted by a chain drive
(D) potential energy of the cars, gained as a chain drive lifts them
(E) potential energy gained by the cars, being achieved while a chain drive lifts them

OA is D. I btw A and D.

For me D has a flaw, since the modifier ("gained as a chain drive...") should describe the nearest noun (in D it is "cars" rather than "energy", so the sentence does not make sense). So I take A, which has several flaws as well (e.g. "being"), but this option make sense.

Please, explain when the modifier can describe the noun, which is not the nearest to modifier.

The word "gained" is a past participle, which acts as an adjective and begins a modifying phrase. The general rule for modifiers is that they should be placed as close as possible to whatever they modify. In this case, "as close as possible" gives the flexibility for the modifier not to be placed right next to "energy." I don't have a hard and fast rule for this type of situation, but if it becomes awkward to force a modifier to be right next to what it modifies, then you can use intervening modifiers such as "of the cars" here. Also, "of the cars" is an essential modifier defining exactly which potential energy, so it could not be omitted.

You're right that answer A uses the red flag word "being," and in general the answer is awkward and wordy. Answer B incorrectly uses the subject pronoun "they" to refer to the possessive "cars'."

Hope this helps!

@spark

Thanks for your post...can you please suggest finally what should be preferred...?? Awkward Op A or Op D which has a modifier issue...

Also can we expect such questions in GMAT...because after looking at Op D i pick Op A...though i agree that Op A is unclear in meaning which is a serious issue in GMAT

Yes, answer D is correct. The modifier is OK in answer D.

You're right that meaning is a very important issue in GMAT sentence correction.

Cheers!

Thanks spark , your input really cleared many confusions .

IMO D.

Spark, thank you