The correct answer is C. eliminate redundancies.
A wordy sentence contains a lot of words and is very long. If you want to shorten that sentence, you will have to read it carefully and look for words that are repeated, or have similar/same meanings, or are just unnecessary because they don't contribute to the sentence. When you eliminate those redundancies, you will fix your lengthy sentences.
A frame narrative is like a fake story so the answer is C
In 'The City in the Sea' Poe explores themes of sin, death, and destruction.
The speaker says that she heard a fly<span> buzz as she lay on her deathbed. The room was as still as the air between “the Heaves” of a storm. The eyes around her had cried themselves out, and the breaths were firming themselves for “that last Onset,” the moment when, metaphorically, “the King / Be witnessed—in the Room—.”</span>
I would say A but D could also be said softly