(c) With a hop and a skip, the door opened, and a little girl came in.
The misplaced modifier here is "with a hop and a skip". Modifiers modify the noun nearest to it. In this sentence, the nearest noun is "the door". However, a door cannot hop and skip. This doesn't make sense. A girl hops and skips. Therefore, the sentence should be said this way instead: The door opened and with a hop and a skip, a little girl came in.