The correct answer to this open question is the following.
Molly, a customer service representative for an insurance company, was rude to one of her customers. The customer immediately contacted Molly’s supervisor and lodged a complaint. Molly’s supervisor then reprimanded Molly and recorded the incident in her file. Molly has made a conscious effort ever since not to repeat the same mistake. This best exemplifies the law of effect.
Psychologist Edward Thorndike developed the concept of "law of effect" in Psychology, in 1898. He concluded that the responses that were satisfying in a specific situation are prone to occur again in similar conditions. And that the responses that produce a discomforting effect are less likely to be repeated. That is why. once Molly's supervisor reprimanded her, Molly tries to avoid that bad conduct because she knows there are consequences to her conduct.