应该是C
in which,这个我还不是很了解,这个句子好多词语不认识,但通过翻译还是知道一些的.所以选C是个猜测,但是有这一用法,这应该是一个非限制性定语从句,你应该打错了,对于非限制性定语从句有一个用法,就是如果从句的谓语部分是动词短语或者说从句就是谓语部分,那么将这个谓语的相应的介词提前.就给你一个例子：The medicine of science, ______ progress has been very rapid lately, is perhaps the most important of all the science.
A. to which B. in which C. which D. with which
答案为B.从句“主谓”结构搭配为：progress has been rapid in, 这里的in意为“在某方面”,相当于rapid progress has been made in the science of medicine.所以将in提前
对于单词认识还是浅薄,所以不确定,但根据大体的条件应该用这个语法.
谢谢!