In a sports team each player has a clear role，and there are few occasions members are confused or uncertain of their roles
A. which
B. that
C. when
D. how
网友回答
A. which
B. that
(答案→)C. when
D. how
解析：when引导的定语从句修饰occasions。occasion意为“时刻，……的时候”，关系副词在定语从句中作时间状语。