Hi WinWinMBA,
Thank you for your question.
Let's start by looking at the first major difference I saw when looking over the question quickly: it vs. they/them. Since the pronoun is referring back to the Central Intelligence Agency, which is a singular noun, the pronoun should match - so let's keep answers A, B, and C because they use the singular "it" or no pronoun at all. Therefore, we can eliminate answers D & E because they use the plural "they" or "them," which is wrong.
Answer C should also go because it doesn't clearly state WHO gets to do the withholding, and it sounds awkward. This leaves us with answers A & B. Let's look at what is different about each one:
A:
enabling it to withhold from the public
B:
for it to withhold from the public
In answer B, using the word "for" changes the meaning of the sentence and the intentions of the Supreme Court. By saying they are awarding the CIA powers "for" a purpose, they are saying that the Supreme Court awarded the CIA more power knowing they would use it for that purpose and ONLY that purpose. This isn't true - they just gave the CIA more power, but it's not clear WHY they did so.
The word "enabling" is a much stronger choice to show that the Supreme Court is giving the CIA power, and that power allows them to withhold information. Using "enabling" shows that the court decision is a cause, and withholding information is an effect, which is the intended meaning. The court didn't give them the power to withhold information directly - they did that indirectly by awarding them more power. Therefore, this is the right answer.
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