Was it near the white building if I may ask Martin Luther King gave a speech I have a

问题补充：

Was it near the white building, if I may ask, Martin Luther King gave a speech I have a dream?

A. where

B. that

C. why

D. in which

答案：

A. where

(答案→)B. that

C. why

D. in which

解析：if I may ask做插入语