A、Because of the great amount of rats she caught. B、Because of her good manner. C、Because of her sudden attack on the burglars.

Martin: Hi there, Pat. How are you?
Pat: Fine, thanks, Martin. I haven’ t seen you for a long time. What have you been up to?
Martin: Oh, studying. It seems that university life is much more time consuming than I originally thought. I don’ t even have time to read newspapers.
Pat: Really? You’ re so busy. You know, I read an article in yesterday’ s newspaper. It is very interesting.
Martin: What’ s it about?
Pat: It’ s about Post Office Cats. They are mouse hunters.
Martin: That really sounds interesting. Could you tell me something about the story now?
Pat: Yes, certainly. The Post Office has actually employed cats since 1868. That means that they have been on the official payroll of the Post Office for more than a hundred years. The loyal public servants appear on the official payroll as  ’ Rodent Operative’ . But we would more easily recognize them under the title ’ Post Office Cat’. They are not employed to sort of deliver mail, of course, but to protect the mail and keep the rodent population under control.
Martin: What do you mean?
Pat: They are mouse hunters. They make sure your morning post arrives nibble-free. You know, they work unsocial hours while we sleep. They hardly ever get a Christmas bonus in their pay packets and can’ t bargain for better conditions. The average rate of pay is no more than a few pounds a month, just enough to pay for their food. But they are allowed to eat all the mice they can catch.
Martin: How come the Post Office had the idea to employ cats?
Pat: Usually the public had to queue inside post offices for their mail. The whole idea of the Post Office employing cats to control the rodent population goes back to the days prior to 1867. As a part of the Jubilee celebrations of Queen Victoria, it was decided that there would be a house-to-house delivery of letters by postmen. As a result, there was a huge accumulation of letters and parcels at post offices. Vast numbers of rats and mice began to hide amongst the mail and nibbled at letters and parcels.
Martin: Yes, I see. They caused great damage to the mail.
Pat: That’ s right. So in 1868, The Post Office Authorities decided to employ cats to keep the rodent population under control. Most of the cats they employed were females.
Martin: why was that?
Pat: Because it was thought that females were better and more persistent hunters than the males. If the number of mice in a post office did not decline greatly after six months, then these cats were to be dismissed from their place of work. London post offices were the first to try out the experiment. Within a few months the rodent population had shrunk dramatically. Other post offices all over the country were soon using cats in the war against rats and mice. Within ten years the pay of the cats was improved from one and a half old pence a day to a six or nine pence a day. Now the average rate of pay is about a few pounds a month. Some of the hard working cats have become quite famous. Have heard of the cat named Lucky?
Martin: No. Tell me the story about her, please.
Pat: OK. Lucky became the most distinguished of all the cats. In 1980, she foiled an attempted robbery in a Worcestershire post office and she did so all on her own.
Martin: How did she do it?
Pat: As the two burglars made their way in through the window, Lucky flew at them. She sank her claws into the back of one of the men and into the neck of the other.
Martin: Oh, I see. This was a surprise attack.
Pat: Yes. This surprise attack was too much for the men and they fled empty-handed. For this heroic behavior, Lucky was awarded the first-ever Post Office DFC certificate. That is the Distinguished Feline Conduct certificate. Another excellent cat was Jerry, of Earls Court post office in London. He served the building for 16 years and was on duty for 24 hours every day. He drove all the mice away from the premises.
Martin: How about today? Does the Post Office still employ cats as mouse hunters?
Pat: Well, there are fewer cats employed by the Post Office than at any time in the past. Their profession is yet another example of a profession laid low by the advances of new technology. With the faster movement of the mail and more hygienic surroundings, Post Office cats are not always needed to keep down the rodent population. But many post offices still employ them and they become great friends with the postmen, who often feed them. When one cat suffered an accident at work, it promptly footed the bill. According to the Post Office, there is no plan for their services to be discontinued in the foreseeable future.
Martin: This is really a fascinating story. Thank you very much.