I really don’t know for certain they discussed.this important event very secretly.A. where

问题补充：

I really don’t know for certain they discussed.this important event very secretly.

A. where was it that

B. where it was that

C. where that

D. it was where that

答案：

A. where was it that

(答案→)B. where it was that

C. where that

D. it was where that

解析：考查强调句型在宾语从句里边的用法。B选项符合。