A、At least 14 miles an hour. B、At least 40 miles an hour. C、At most 40 miles an hour. D、At most 14 miles an hour. C细节题。通过浏览选项可知

One winter evening Mr. Blake was driving in his car along an isolated country road. He had been to New York, in which he had withdrawn 10,000 dollars from the bank.
    He was then going back home with the money, which he had put in his pocket.  At the loneliest part of the road a middle-aged man in poor clothes stopped him and asked for a lift. Mr. Blake told him to get into the car and continued on his way.  As he talked to the man he learned that he had been in prison for robbery and had escaped out of prison three days ago. Mr. Blake was very worried at the thought of the 10,000 dollars in his pocket.
    Suddenly he saw a police-car and had a clever idea.  He had just reached a small town where the speed limit was 40 miles an hour. He pressed down the accelerator and drove the car as fast as it would go. He looked back and saw the police-car had seen this and had begun to chase him. After a mile or so the police-car overtook him and ordered him to stop.