I never heard an impatient word passed between any members of my group ___ the time came to decide t

题目

I never heard an impatient word passed between any members of my group ___ the time came to decide the individual tasks to be undertaken.
A.and B.when C.that D.since
Which one?Why?

答案

B.When.这个句子的意思是,当到分配每个人要着手的任务的时候,我从来没有听过一句不耐烦的话语在我的任何一个组员之中.当.时候,正是When