A、an orchestra conductor B、a music fan C、a sales manager in a music company D、a background music composer D

Bill: Hi, Howard. What are you working now?.
Howard: Hi, Bill. Hi, Lisa. I’ve just finished a piece of background music.
Lisa: Background music? Oh, like the music they’re playing here now.
Howard: Yes. You hear it everywhere--in restaurants, airports, supermarkets, department stores...
Bill: In banks, too. I noticed it while we were at the bank today.
Lisa: Did you? I didn’t.
Howard: You’re not supposed to notice it. It’s just there, in the background. It’s supposed to influence your attitudes, put you in the right mood.
Lisa: I’m not sure I like that idea.
Howard: Well, it seems to work. Companies pay millions of dollars every year for background music. It’s supposed to give you a better feeling about yourself and the people around you. Factories use it a lot. It makes the workers happy, and they work better that way. In one factory, music increased production 4.5 percent.
Bill: I should think they’d get tired of hearing music all day.
Howard: They don’t, though. One fellow in San Francisco told me, "If the music stops, somebody always runs to the telephone to complain.”
Lisa: Now that I think about it, I can’t remember when there wasn’t background music in restaurants and stores.
Howard: That shows how young you are. Actually, it all started during World War II when some factories had their own orchestras to keep workers happy and calm. Now, of course, the music is piped in by a machine, and different kinds of music are played at different times during the day. They play faster music at ten in the morning than at eight, for instance, because workers tend to be slower then.
Bill: What about restaurants? Do they play the same music for dinner and lunch?
Howard: I don’t know about that, but I do know that hamburger places play fast music. When they started playing faster music, they found that a customer spent only seventeen minutes eating. The time was twenty-two minutes before that.
Lisa: So they have more people coming in and out to buy hamburgers.
Howard: Exactly. And that’s good for business. You can see why music has become so popular. In Los Angeles, for instance, thirty different companies are selling background music services.
Lisa: I still think there’s something about it that I dolor quite like.
Howard: I know what you mean, but lots of people would not agree with you. The Xerox Corporation in Rochester, N.Y. spends more than $ 80,000 a year for background music. Prisons use it, and farmers use it to keep their cattle calm. It’s even supposed to have an effect on plants.