My friends, after they heard what had happened to me, ________ said it sounded like an adventure．

A.all

B.that

C.which

D.who

答案及解析： A

解析：

此题可把after they heard what had happened to me去掉，就非常容易地看出此题不是定语从句，all用来说明“我所有的朋友”，故选A。