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

考查定语从句，先行词是Gun control，指物，关系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，选C。