一道又争议的GWD题

I think C it is.

Logically, the sentence the drug’s maker charges for another product with the same active ingredient is an attributive clause of price, since as or than does not intruduce an attributive clause here, choice A and B are wrong.

In D and E, what and which represent price, but we know charges is a transitive verb, we can say charges 10 yan for a haircut but not charges at/of 10 yan, so these two choices  are wrong.

In C, that represents price and this pronoun is object of the verb charges in the attributive clause.

Hi, Can u explain it for me when "as" can be used as a relative pronoun?

请参考。

RonPurewal -Manhattan Gmat Instructor

this one isn't that bad if you get down to the "skeleton" of the sentence. to do that, you should kill intervening prepositional phrases that don't affect the grammar of the main sentence.
to this end, you can simply get rid of the following:
"per milligram"
"for another product"
"with the same active ingredient"
and you're left with:
a new drug is being sold for three times the price ____ the drug's maker charges.
  
once you see this, it should be more clear that (c) is the correct answer. if you're a non-native speaker and you can't recognize "that" as the word belonging in that blank, then here's the reason: it's because "price" is the direct object of "charges". when you turn around such constructions, you use "that":
i hit the ball --> the ball that i hit
she delivered the baby --> the baby that she delivered
etc.

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Why E is wrong?

unidiomatic.

you can't say that the drug's maker "charges at a price" for the drug; therefore, the derivative construction "the price ... at which the drug's maker charges" is also wrong.
the correct idiom is "charges a price"; i.e., "price" is a direct object here. therefore, you have to say the price that the drug's maker charges.


it's idiomatically correct to say that the drug's maker sells the drug at a price (which would be the price at which the drug's maker sells the drug), but we aren't using "sell" here.

i'm surprised to see "the drug's maker", a phrase that i would think gmac would consider "awkward". i'd expect to see "the maker of the drug" instead.

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why is D wrong?

you have to read these things very, very literally.

"what the drug's maker charges" is ... guess what ... a price.
therefore, "three times the price of what the drug's maker charges" would refer to the price of a price. that is illogical.
this construction is thus not only "wordy", but actually nonsensical.

这个the price of a price...解释的不错。