The underline part of the sentence

the answer should be b.

explanation:

it should be b because she researched before writing so it would be in past tense. "the author researches her subject before she had written the first draft.

and your question what topic are you in trouble with?

remember, the goal of an adjective clause is to add more information to a noun or a pronoun. as you can see from the examples above, you can add information by including a longer adjective clause or tighten up a sentence by turning the adjective clause into an adjective phrase.

answers may vary, but my guess based on my personal education it has alwats been 3 or 4