The incident turned him into different person even if he did not realize it at beginning.

问题补充：

The incident turned him into different person, even if he did not realize it at beginning.

A. a; a

B. the; the

C. the; a

D. a; the

答案：

A. a; a

B. the; the

C. the; a

(答案→)D. a; the

解析：句意：这次事件使他变成了一个不同的人，尽管开始时他没有意识到。泛指一个……的人，用a，而at the beginning起初，开始。是固定短语。所以选D。