The correct answer is A.<span>could not be heard above the voices in the hallway
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B is a subject, C is an adverbial of reason, while D is an adverbial of manner.
I'd say the correct answer is the second option. Because while he was alive, Poe lived in poverty because he couldn't earn enough writing poems and stories, he also had to get a job as a critic. Only after he died did people start realizing the importance of Poe's work. And King is still alive, and still popular, receiving numerous awards for many of his works.