As soon as Linda went into the department that sold raincoats, she sensed there was something unusual in the atmosphere. First of all, there was a salesman there and not a saleswoman. That was very unusual in the women’s coat department. The salesman asked if he could be of any help. But when she said she was just looking he did not seem to be listening. He (lid not look very much like a salesman, either. A second later a raincoat caught her eye. Site asked him a question about it. He did not even hear her at first. She asked again. She wanted to know if he had any coats like it with a detachable (可分离的) lining. He did not seem to understand what a detachable lining was. She explained. Then she went on looking. She noticed that the salesman seemed to be watching another customer in the department all the time. The other customer, a middle-aged woman, left the department. The salesman immediately went to the phone and told somebody on the other end that the woman had gone and had definitely taken two leather belts without paying for them. Then he turned to Linda and explained that he was not a salesman at all but a store detective. Later, Linda read in the paper that a woman had been arrested for stealing some belts front a department store, or, in other words, for shoplifting. The salesman ______.

A. received Linda warmly
B. was attending another customer
C. knew raincoat well
D. was a store detective