It was clever __________at the answer in two minutes.

It was clever __________at the answer in two minutes.
A、of him to arrive
B、for him to arrive
C、for his arriving
D、of his arriving
【正确答案】：A
【题目解析】：比is+形容词+of+名词/代词+不定式，of后的名词/代词为不定式的动作发出者。