Steven Spielberg's classic movie Jaws was a thriller about a great white shark that terrorized tourists at a local beach. Just before the shark's appearance, eerie music began playing. As the unseen shark came closer, the tempo of the music picked up. After the audience had experienced this a few times, the sound of the music triggered the emotional reaction of fear in the audience even though the shark still had not appeared. At that point, the sound of the eerie music was a(n):_____
A. unconditioned response (UCR).
B. conditioned response (CR).
C. conditioned stimulus (CS).
D. unconditioned stimulus (UCS).

Conditional stimulus: The conditioned stimulus was a neutral stimulus before using in the classical stimulus. The conditioned stimulus was associated with the unconditioned stimulus and triggered the conditioned response. Ivan Pavlov was the first person who used cs, us, UCS, UCR, etc in classical conditioning. Ivan Pavlov noticed that the dog salivate naturally when seeing the food but when food is not delivered and the dog watched only a white coat of lab assistant who delivered the food to the dog even started salivating.

NS lab assistant

US food

UR salivation