Every Time Brandy Drops a Cricket into the Cage of Her

Every time Brandy drops a cricket into the cage of her pet tarantula, Chompers, he begins to salivate. Brandy has gotten in the habit of playing her favorite CD when she feeds Chompers. After several pairings of the cricket and her favorite CD, all Brandy has to do is play the CD and Chompers begins to salivate. In this example, Chompers's salivating to the fresh, wriggling cricket is a(n)

A) unconditioned stimulus.
B) conditioned stimulus.
C) unconditioned response.
D) conditioned response.