恩格斯说：“我们只能在时代的条件下进行认识，而且这些条件达到什么程度，我们就认识到什么程度”。这说明                        (　　)

A．客观条件妨碍人的认识能力的提高

B．认识客观事物是时代的要求

C．人类的认识能力是有限的

D．人的认识能力受客观条件的制约

—I called you last night, but you didn’t answer it.

—I’m terribly sorry. I ______ a meeting at that time.[ ]

A. had

B. was having

C. am having