阅读下面短文，请从短文后所给各题的4个选项(A、B、C、D)中选出一个最佳选项。 

     Mary was watching a mystery movie on television. The end of the movie was near, and she was totally absorbed. Then her baby started crying. She shouted at him to shut up. In response, he cried louder. She got angry and shook him, but the baby cried even louder. In the meanwhile, the mystery’s conclusion took place and she missed it. Angrily, she hit her son in the face. In this situation, someone was pursuing a goal—seeing the end of an exciting television show, but something happened to block the achievement of that goal. The person thus became frustrated, anger built up, and direct aggression occurred.
     However, aggression is not always aimed at the person who causes the frustration. Consider a businessman who had a hard day at the office. He was about to close a deal with a customer when his boss awkwardly interfered, and he lost the sale. On the way home in his car, the frustrated businessman blew his horn angrily at a car ahead when it didn’t pull immediately away from a traffic light. As he entered his home, his dog jumped up joyfully on him, only to receive a quick kick. He then shouted at his wife during supper. All these aggressive behaviors are examples of displaced aggression—aggression placed on the wrong person. Aggression against the person who causes the original frustration can often be harmful. In this case, attacking or swearing at the boss could cost the businessman his job. When the person who causes the frustration has power over the frustrated person, aggression may be shifted onto a person who has nothing at all to do with the original frustration.