Answer:
D because that's the only one where the author does anything semi-significant.
Explanation:
Helps is the answer there
D -- Erin and Maria are going to the mall, and John is going to the movies.
Remember, compound sentences contain TWO subjects (Erin, Maria, and John. Though Maria and Erin are technically two, they are doing the same thing in that sentence, and qualify as one compared to John) and a predicate.
I hope this helps you!
xo, Leafling
