Answer:
Jake is using C. shaping to train Peach to roll over.
Step-by-step explanation:
In Psychology, shaping is the process of reinforcing behavior until it reaches a final desirable behavior. That means, when teaching an animal to do something, we should first reward the animal for any sort of response that resembles the target behavior. Later on, we should stop rewarding it for any response and only do it if the response is closer to our goal. This pattern should keep on going until the target behavior is achieved. The behaviorist B. F. Skinner did important researching on this matter and was even able to teach a pigeon how to bowl.
What Jake is doing with Peach is precisely that. First, he reinforces any desirable responses (sitting). With time, he stops rewarding any type of response but, instead, rewards the ones that more closely approximate the target behavior (lying down). Finally, he reinforces only the behavior he wanted Peach to learn (rolling over).