Don't talk to the bus driver while he is driving------th

Don't talk to the bus driver while he is driving______the bus.
A.in front of B.in the front of C.at the bank of D.at back of
选项是B
司机开车不可能在车的后面,排除选项C和D.
in front of指在某物的前方.
in the front of指在某物的【内部靠前】的地方.
如：
There is a tree in front of the classroom.
教室的前面有一棵树．
There is a blackboard in the front of the classroom.
教室的前面有一个黑板．