Peggy wanted to teach her dog how to roll over. She tried giving him instructions, but it didn't work. She tried waiting for him to roll over so she could reinforce the behavior, but she had to go to bed before the dog rolled. Finally, she began reinforcing the dog when it made behaviors that more closely resembled rolling over. At last, using , she was able to teach the dog to do the trick.

The answer is shaping.

Explanation:

In operant conditioning, shaping refers to rewarding similar behaviours to the target, until the objective is achieved. This is based on the concept of "successive approximations". For example, if a researcher is trying to teach a rat to pull a lever, he might reward other similar behaviours such as standing near the lever. Then, the rewards stop and another action (e.g. touching the lever) is reinforced. Eventually, the rat should be able to pull the lever.

shaping

Explanation: Shaping also known as or behavior-shaping, is a type of operant conditioning that modifies behavior by reinforcing behaviors that progressively close to the target behavior. It is used in experimental analysis to train organisms to perform behaviors that would rarely have occurred if it ever occurs. Here, instead of waiting for a organism to develop an operant response (desired behavior), any response leading to the operant response is rewarded. By reinforcing the dog when it made behaviors that more closely resembled rolling over, Peggy was able to push it to learning how to actually roll over.

the answer is d. amendments.