阅读下列短文，然后根据短文的内容从每小题的四个选择项中选出最佳的一项。

     Some people do not like anything to be out of place, they are never late for work; they return their books to the library on time; they remember people's birthday and they pay their bills as soon as they arrive. Mr. Brown is such a person.
     Mr. Brown works in a bank, and lives alone. The only family he has were in the next town: his sister lives there with her husband, and her son, Mark. Mr. Brown does not see his sister, or his family, from one year to the next, but he sends them Christmas cards, and he has not forgotten one of Mark's seventeen birthdays. Last week Mr. Brown had quite a surprise. He drove home from the bank at the usual time and drove neither too slowly nor too fast; he parked his car where he always parked it, out of the way of other cars, and he went inside to make his evening meal. At once, there was a knock at the door. Mr. Brown opened the door to find a policeman standing at the door.
     "What have I done wrong?” Mr. Brown asked himself. "Have I driven on the wrong side of the road? Has there been some trouble at the bank? Have I forgotten to pay an important bill?”
     "Hello, Uncle”, said the policeman, "My name's Mark.”