A father and his little son are going home. The boy is five years old. He is interested in(---) all kinds of things and he is always asking questions. "What's the meaning  of the word 'drunk '?" asks the boy. "Well, my son," his father answers. "Look, there are two policemen. To a drunk man's eyes, there are four." "But, Dad, there is only one policeman." In fact , how many policemen are standing there?
Two. One. Three. Four.