He talked about a hero ____ no one had ever heard.

He talked about a hero ____ no one had ever heard.
A、of whom
B、from whom
C、about that
D、who
【正确答案】：A
【题目解析】：【考点点击】本题考查介词+关系代词。【要点透析】关系代词前介词的选择可根据定语从句中动词的习惯搭配来确定。 hear of意为“听说”,且定语从句的先行项 hero为人,在定语从句中作宾语,关系代词需用whom,故选A.