Until she spoke ________ she was

Until she spoke ________ she wasn't Chinese.
A、hadn't I realized
B、didn't I realize
C、I hadn't realized
D、I didn't realize
【正确答案】：C
【题目解析】：本句没有否定词位于句首，因此不用倒装。同时，在过去的时间点之前发生的事情，用过去完成时表示。