Questions 17 to 20 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now, listen to the passage. Why did the speaker once assume the manager was sick
A．Because he looks very unhappy. B．Because he usually wore a hard wing collar. C．Because the left side of his face was swollen. D．Because the right side of his face was swollen.