Final answer:
The UCR in the scenario of Jim's cat salivating at the sound of the can opener is the cat's salivation, which is its natural, unlearned response to the Unconditioned Stimulus, the cat food.
Step-by-step explanation:
When Jim's cat begins to salivate at the sound of the can opener, we are discussing a concept from classical conditioning in psychology. In this context, the Unconditioned Response (UCR) is the cat's salivation. The UCR is a natural reaction that occurs without prior learning or conditioning. This reaction is the cat's automatic response to the Unconditioned Stimulus (UCS), which is the cat food. When the can opener's noise (Conditioned Stimulus or CS) consistently precedes the presentation of the cat food, the cat learns to associate this sound with feeding time, leading to the salivation (Conditioned Response or CR) even when only the sound of the can opener is heard.