Luckily, the poor boy had enough money he could buy a train ticket.A. by whichB. on which

Luckily, the poor boy had enough money he could buy a train ticket.
A. by which
B. on which
C. with which
D. for which

A. by whichB. on which(答案→)C. with whichD. for which解析：考查定语从句。定语从句中的关系代词可以与介词连用，介词可以根据先行词的搭配，也可以根据短语从句中的搭配，也可以根据句子的意思，本题就是根据句子的意思。句意：幸运地是，那个可怜的孩子有了足够的钱，用这钱，他买了一张火车票。With表示使用…；故C正确。

哦，回答的不错