Keep in mind that a compound predicate has two or more verbs.
Based on that information alone, we can eliminate A and B. With C, this one seems like it could work, but it actually doesn't. The verb in that sentence is "enjoy", and in this case, "skiing" and "skateboarding" are nouns. (because they're the object of the predicate verb.) That leaves D as the answer!
Hope I helped! :)
tl;dr: The answer is D!
