The answer is D.
Compound sentence uses one independent clause and one dependent clause. In option D, “after they finished studying” is the dependent clause. “Juan and Maria went to the movies” is the independent clause.
From the above excerpt the fact which best support Peter's opinion is that STUDENTS WHO PLAY AN INSTRUMENT GET BETTER GRADES THAN STUDENTS WHO DO NOT. This can be inferred from the passage: Peter considered playing an instrument a lot of fun; playing musical instruments is great for brain development. It helps the brain develop neurophysiological distinction which helps students distinguish between certain sounds that can aid in literacy.
Above-on top of something
below- under something
up- "going up"
down- "go down the street"
C. the author is the answer.
