关于英语语法 as well as 迫切想知道!

关于英语语法 as well as 迫切想知道!
My sister as well as her classmates who ( )late for class ( )criticized by Mr Li.
A.were was
B.was was
请问选哪一个好?who引导的从句在这里修饰的是my sister还是her classmates?
如果说who引导的定语从句是修饰my sister的,那么为什么放在classmates后面这样不就有点语意上的不清楚了吗?有如果who引导的定语从句是修饰classmate的,那么根据as well as 来分析,这个短语又是强调前者而不是强调后者,也很矛盾.