An experiment finds that a certain male subject always has an increased heartbeat when he hears a certain piece of music. the experimenter sounds a buzzer and then plays the piece of music. the experimenter repeats this procedure until the man responds with an increased heartbeat to the sound of the buzzer alone. in this situation the unconditioned response is the:
a. increased heartbeat.
b. piece of music.
c. sound of the buzzer.
d. listening to the music.