【英语】She brought with her three friends ,none of( )had ever met before

题目

【英语】She brought with her three friends ,none of( )had ever met before
A.them B.whom
答案选B,我觉得A也对
请帮我辨别一下 O(∩_∩)O谢谢

答案

B,考察定语从句,选A的话要在逗号后面加上and