Question

a writer sometimes chooses to end a sentence with a preposition because doing so makes the sentence more
grammatical
awkward
formal
clear

Explanation:

Ending a sentence with a preposition is often done to avoid awkward, stilted phrasing and make the meaning of the sentence more direct and easy to understand. The other options are incorrect: ending with a preposition is not required for grammatical correctness (it is grammatically acceptable in modern English), it does not make a sentence awkward (avoiding it can create awkwardness), and it is less formal, not more formal, than rearranging the sentence to place the preposition earlier.

Answer:

clear