问题
_______ , the car stopped all at once.[ ]
A: Seeing a boy lying on the ground
B: The minute the driver saw a boy seated on the road
C: On seeing a boy sitting on the ground
D: The driver saw a boy standing on the road
B: The minute the driver saw a boy seated on the road
C: On seeing a boy sitting on the ground
D: The driver saw a boy standing on the road
正确答案是：
