I think Vic feels surprised by the fact（）I' m smarter than he is

I think Vic feels surprised by the fact（）I' m smarter than he is.
A、why
B、which
C、when
D、that
【正确答案】：D
【题目解析】：【应试指导】本题考查同位语从句。句意：我认为维克对我比他聪明的事实感到惊讶。分析句子结构可知，本句为内含同位语从句的复合句。同位语从句常用来修饰一些表示抽象意义的名词，如belief，，doub，fact，hope等，引导词常用that。故题选D。