Hello :)
A linking verb is a verb that describes a subject, a linking verb connects a noun and a predicate.These verbs always link subjects to something that further describes the subject of the sentence.
A does not contain a linking verb, but it does contain a helping verb; "has". B does not contain a linking verb, but it does also contain a helping verb; "are" C doesn't contain a linking verb, but some might get this mixed up because is has the word have which is a linking verb, but in front of that word it says "could" indicating that it didn't happen. D does contain a linking verb "have been" this indicates that they've been feeling this way. The hockey players is the noun and anxious about the match is the predicate.
So i'm inferring that the answer is D