Option “A” is the correct example of a sentence that has a
compound predicate. The sentence is “She washed the shells and dried them in
the sun”. A compound predicate actually consists of two or more than two verbs
having the same subject and joined by any conjunction like “or” or “and”. As
far as the given sentence is concerned, we see that “She” is the subject and
the subject is doing two different things.
This is the reason behind taking this sentence as a compound predicate.