Choose the option that supplies the correct verb and the correct explanation for the verb choice in the following sentence: The window fans and the air conditioner stored in the walk-in closet downstairs.

(A) The verb should be is. When two subjects are joined by and, they are considered separate subjects and the verb should agree with the subject closest to it, air conditioner.
(B) The verb should be are. When two subjects are joined by and, they are considered separate subjects, and the verb should agree with the subject listed first in the sentence, window fans.
(C) The verb should be is. When a compound subject is followed by a prepositional phrase, the verb should agree with the object of the preposition, closet.
(D) The verb should be are because a compound subject joined by and always requires a plural form of the verb.