Do you know the lady your sister is talking?A. which B. with whom C. whom

问题补充：

Do you know the lady your sister is talking?

A. which B. with whom C. whom

答案：

解析：本题考查的是定语从句，关系代词的选择，根据先行词为人，故将A排除，又因为关系代词在从句中作宾语，故选B