okay so i've been talking to Ron about this offline, and although we haven't come to a full agreement on what is required in this sentence (he and i have different interpretations that both lead to C as a correct answer, which is all that really matters!), under his approach you can actually make &...

If there are two roadblocks, X and Y, and they ask what is necessary, you are looking for an answer choice that eliminates X, or Y, or both. Note that only one of these three will actually be an answer choice. If the questions is one of sufficiency, the correct answer choice will eliminate both X a...

ron, so can we follow this rule ? i'd be hesitant to posit this as an actual rule. i think that the more precise rule is like this: if the actual object of the preposition is the verb , not the noun, then you can't use this construction. here's what i mean: you can't say "my parents heard abou...