After checking the report ,（ ）.

After checking the report ,（ ）.
A、several mistakes were discovered
B、several mistakes are discovered
C、the manager discovered several mistakes
D、the manager will discover several mistakes
【正确答案】：C
【题目解析】：根据前半句的checking可知后半句的主语要与check是主动关系，故可排除选项A和B；after意为“在......之后“，所以要用一般过去时，故选C。