【单选题】

Policeman: OK, buddy, your driving license. How fast were you going
William: Well it was about 50 mph or less. I was driving very slowly.
Policeman: 50 mph ______ All right. That'll be one hundred dollars.

A．Don't you know the speed limit downtown is 40 mph

B．Don't you know the controlled speed downtown is 40 mph
C．You need to fix your car.
D．You drive in the wrong way.