【单选题】
Jack went to a barber’s shop and had his hair cut, but he was not happy with the result(结果). When his friend Bob saw him, he laughed and said, "What has happened to your hair, Jack"
Jack said, "I tried a new barber’s shop today, because I wasn’t quite satisfied with my old one, but this one seems even worse."
Bob agreed. "Yes, I think you’re right, Jack. Now I’ll tell you what to do when you go into a barber’s shop next time: look at all the barber’s hair, find out whose hair looks worst, and then go straight to him."
"Why shall I go to him" Jack asked.
"Who cut that man’s hair" answered Bob. "Just think it. He couldn’t cut it himself, could he Another barber cut it. So you know he can’t be the worst barber.\
Bob told Jack to go to the barber with the worst hair next time.