You just observed one of your sales clerks yelling at a customer to, "Hurry up, other customers are waiting!" That behavior is far from what you expect from your sales clerks. It is your expectation that they will be accommodating and patient with all of your customers. As a result, you call the sales clerk aside and tell him that you will not tolerate your employees yelling at customers. You also end his shift early – without pay. Which form of reinforcement did you use? a. Negative
b. Extinction c. Positive d. Punishment