Final answer:
Counterconditioning is indicated when an association with a positive stimulus (food) changes a pet's previous aggressive or fearful reaction to another pet into a calmer, more pleasant response. The correct option is c.
Step-by-step explanation:
The form of conditioning exemplified when the owner feeds the dog and the cat side by side and they begin to like each other is known as counterconditioning. This is a process by which the pet's fearful or aggressive response to a stimulus is replaced with a more pleasant, toned-down response.
Essentially, the presence of the other pet becomes associated with something enjoyable (food) and gradually, the initial negative response diminishes.
Hence, Option c is correct.