I have many foreign friends some are businessmen. A. of them B. from which C. who of D. o

问题补充：

I have many foreign friends, some are businessmen.

A. of them

B. from which

C. who of

D. of whom

答案：

A. of them

B. from which

C. who of

(答案→)D. of whom

解析：考查定语从句。先行词为foreign friends，of whom即some of foreign friends其中的一些外国人，故选D。