单选题 One of the most extraordinary things about the First World War was the enthusiasm ______ the majority of soldiers went off to fight for their country.
A. in that B. for which C. with which D. for that

【正确答案】 C
【答案解析】[考点] 关系代词用法辨析
[解析] 介词with表示“凭借”，可以与which连用引导定语从句。故C项为正确答案。