—I hear that Lily’s brother is a worker here.—Look the man is working over there is her

问题补充：

—I hear that Lily’s brother is a worker here.

—Look, the man is working over there is her brother.

A. who

B. whom

C. what

D. which

答案：

(答案→)A. who

B. whom

C. what

D. which

解析：考查定语从句的关系代词。who “代替人”作主语或者宾语；whom “代替人”作宾语；what不用于宾语从句；which“代替物”作主语或者宾语；先行词为人， 在从句中作主语。故选A。