Question

Gun control is a subject ____ Americans have argued for a long time.

   A．of which   B．with which   C．about which   D．into which

Answer 1

C

解析：考查定语从句，先行词是a subject，指物，关系代词词在从句中做介词的宾语，介词前置，介词与从句动词构成搭配argue about sth，故选C。