The gentleman ________ you told me yesterday proved to be a thief．

A.who

B.about whom

C.whom

D.with whom

答案及解析： B

解析：

搭配“tell sb．about/of sb．/sth．(向某人讲有关某人/某事)”中的sb．在定语从句中由关系代词whom代替，介词about/of可提前。