After the exam my teacher told me that failure the mother of success.A. wasB. isC. be D.

问题补充：

After the exam, my teacher told me that failure the mother of success.

A. was

B. is

C. be

D. been

答案：

A. was

(答案→)B. is

C. be

D. been

解析：考查时态。根据句意可知描述的是客观真理，时态用一般现在时，故选B。