it was only then( )how much trouble I had caused to him.A.when I realizeB.did I realize C.that I realizeD.that did I realize

it was only then( )how much trouble I had caused to him.A.when I realizeB.did I realize C.that I realizeD.that did I realize
it was only then( )how much trouble I had caused to him.
A.when I realize
B.did I realize
C.that I realize
D.that did I realize

it was only then( )how much trouble I had caused to him.A.when I realizeB.did I realize C.that I realizeD.that did I realize
c应改成that I realized

C. that I realize这是个强调句，强调那时侯我才发现我给他带来了好多麻烦。

C. that I realize (绝对答案)