I heard the news（） ,believe it or not,he had got the first place in the English competitionA that B whichC asD what

I heard the news（） ,believe it or not,he had got the first place in the English competition
A that
B which
C as
D what

A,我听说了一个消息,信不信由你,他在英语竞赛中得了第一,believe it or not作插入语

A
不管你相信与否，我听说他在英语竞赛中取得了第一名。
用that引导了同位语从句，而其余几个连词不能引导同位语从句。

B.