bobby and Sue were parked at Lover's Lane. When Bobby kissed Sue, his breathing accelerated. Sue always wore Chanel #5 when she went out with Bobby, whenever Bobby smelled Chanel #5, he began to breathe faster. Sue's kiss was the: a. UCS b. UCR c. CS. d. CR.

The answer is a. UCS (Unconditioned stimulus).

Explanation:

In classical conditioning, a conditioned stimuls is associated with an unrelated consequence, called unconditioned stimuls. This produces a reaction known as conditioned response.

In the example, the smell of the perfume was associated with the kiss, which resulted in heavy breathing. It's important to realise that any neutral stimulus can become conditioned. This means, if Sue had worn any other perfume, Bobby would have reacted the same way.