If this is how you've presented the question, Its a bit hard to answer it when one hasn't read these books. It'd be best if you'd put both books into a summary for us to go based off of, at most.
It is D: to brainstorm by putting thoughts onto paper without regard for spelling or mechanics. the reason being is nobody but yourself is going to look at the free write.
Answer:
The answer to your question would be that the revision that combines the sentence using a subordinating clause and subordinating conjunction is the following one: East Antarctica is covered by massive layers of ice which is thousands of meters thick.
Explanation:
The revised version of the sentence includes an essential relative clause. Essential relative clauses limit an ambiguous noun, that is, they complete the meaning of the sentence. The essential clause helps identify the noun it modifies. Consequently, if they are dropped, the meaning of the sentence is altered (see 1).
1) East Antarctica is covered by massive layers of ice
