Answer: D) On vacation, we went swimming, diving, and canoeing.
Explanation: Parallelism is a literary device that consists in the repetition of grammatical structures of words or phrases, in order to maintain a symmetry in the text. In the given sentence, we have a list of activities, they should be all in the same grammatical structure in order to maintain the parallelism, so if it says "swimming" and "diving" all the elements should have the "-ing" form, so the correct answer is "On vacation, we went swimming, diving, and canoeing."
