Hotlines have become common in China. Some radio broadcasting stations use hotlines to encourage the listeners to take part in the talk shows. That's a good idea. Yet, the fact is, some people do nothing but break the whole program. Some people know little about the topic under discussion. Sometimes they do not even know what the host is talking about. So the host has to tell the caller what the show is about. Usually the caller will ask a few questions which express his hope and show his ignorance  . Then the host has to answer and explain--how silly this is! It wastes a lot of time. It seems that some people phone the hotlines for fun. They just want to let the listeners hear them. They don't care what the topic is, whether they themselves are interested or how silly they appear to be. I'm totally bored by those people. It's necessary for radio stations to improve the hotline programmers. In my opinion, if a caller does not know what is going on, the operator should not let the caller take part in it. Some calls waste the host's time   _  .
because the host works hard because of the caller's ignorance because the host likes talking to the caller because of a lot of questions raised by the caller
Question: Hotlines have become common in China. Some radio broadcasting stations use hotlines to encourage the listeners to take part in the talk shows. That's a good idea. Yet, the fact is, some people do nothing but break the whole program. Some people know little about the topic under discussion. Sometimes they do not even know what the host is talking about. So the host has to tell the caller what the show is about. Usually the caller will ask a few questions which express his hope and show his ignorance  . Then the host has to answer and explain--how silly this is! It wastes a lot of time. It seems that some people phone the hotlines for fun. They just want to let the listeners hear them. They don't care what the topic is, whether they themselves are interested or how silly they appear to be. I'm totally bored by those people. It's necessary for radio stations to improve the hotline programmers. In my opinion, if a caller does not know what is going on, the operator should not let the caller take part in it. Some calls waste the host's time   _  .
A. because the host works hard
B. because of the caller's ignorance
C. because the host likes talking to the caller
D. because of a lot of questions raised by the caller
Answer: