Answer:
The answer is C. At that point, the sound of the eerie music was a conditioned stimulus.
Explanation:
In this case, the unconditioned stimulus was the appearance of the shark, that automatically triggers fear in the audience, fear is the unconditioned response at this point, it is automatic. When the unconditioned stimulus, begins to be associated with the sound of the music so that, eventually, the sound of the music alone triggers the same fear, the sound of the music becomes the conditioned stimulus; in the same way, when fear is triggered by the sound of the music alone, fear becomes the conditioned response.