---Oh，he turned to Professor Lee for advice.

A．Was it how that

B．Was it that how

C．How was it that

D．How it was that

【答案】C

【解析】考查强调句。句意：他是如何解决这个问题的？他向李教授求助的；强调句的特殊疑问句结构 特殊疑问词+is it that+ 其它。