“知之为知之，不知为不知，是知也”的恰当英文翻译是（）。

A、When you know a thing, to hold that you know it. When you do not know a thing, to allow that you do not know it. This is knowledge.

B、When you know a thing, to recognize that you know it, and when you do not know a thing, to recognize that you do not know it. That is knowledge.

C、If you know it, say you know. If you don’t know it, say you don’t. That is knowledge.

D、When you know a thing, say that you know it; when you do not know a thing, say that you do not know it. It is wise doing so.