The subject ____ we are going to turn is about English study.
A. about which B. with which C. about that D. to which
The subject ____ we are going to turn is about English study.
A. about which B. with which C. about that D. to which
D
解析：turn to意为“致力于……”，to为介词，which引导一个定语从句，修饰先行词“the subject”。