综合一贯制运输是指将汽车的机动灵活和铁路、海运的成本低廉(便利和经济)以及飞机的快速的特点组合起来，完成“门到门”运输。

It was not until the accident happened _______ aware of my own foolishness.  [ ]

 A. did I become                    

B. when I became  

C. had I become                  

D. that I became