Freddie used to feed her cat canned food. Now every time uses the can opener gets very excited and start meowing. In this example UR is?

Here's why:

* Unconditioned Response (UR): A natural, unlearned reaction to a stimulus.

* Unconditioned Stimulus (US): The stimulus that naturally elicits the UR.

In this case:

* US: The canned food itself.

* UR: The cat's excitement and meowing, which are natural reactions to the presence of food.

Freddie's cat has learned to associate the can opener (the conditioned stimulus) with the canned food (the unconditioned stimulus) and now responds with excitement (the conditioned response) to the can opener alone.