The sentence that is a compound sentence would be B. Since it provides 2 mail points or actions combined within a single sentence, there are 2 main events occurring within the sentence whereas the other options only describe one.
Mark saw the kangaroo, but he didn't take a picture.
Both Mark seeing the kangaroo and not taking the picture are these events combined within this sentence.
it allows for you to precisely focus on one part of a broad topic. It allows for you to be able to point out the minuscule details within a topic versus focusing on the broad topic of a whole.
