Even a child knows that nodding the head means "Yes". But some people will probably be puzzled when they first come to India. When they talk to an Indian, he often shakes his head. They might think that the Indian does not like what he said, but _ he is expressing agreement. The Indians have a habit of shaking their heads slightly when they talk to somebody. It doesn't mean "No", but "Yes". If a person doesn't know this, it might cause misunderstanding. At one time a foreigner in Indian told his driver who was an Indian to take him to his office. The driver shook his head. The foreigner repeated his request and the driver shook his head again. At last, the foreigner shouted angrily, "Drive me to my office at once!" The driver said in a low voice, "Yes, sir," smiling and shaking his head again at the same time. Why did the Indian driver shake his head when the foreigner asked him to drive him to his office? Because   _  .
the Indian driver had something important to do the foreigner promised to give him only a little money the driver felt uncomfortable at that time in India shaking the head means agreement