Ais not the right answer because a compound sentence contains two sets of subject and verb pairs. A compound sentence is basically two simple sentences that are "compounded". (B) is not the right answer because a compound sentence can contain a comma and a conjunction or a semicolon. An example of a compound sentence with a semicolon is "I did not eat the disgusting dinner; I snuck some cereal instead". (C) is the correct answer because a compound sentence contains TWO simple sentences, not one. This rules out (D). I hope this helps!
