He planted a tree on the hill his father who died 3 years ago.A. in memory of B. in order

问题补充：

He planted a tree on the hill his father who died 3 years ago.

A. in memory of B. in order toC. instead of

答案：

解析：他在山上种了一棵树以纪念三年前去世的父亲。in memory of：作为对某人的纪念， in order to：为了，目的是，instead of;代替。根据句意可知应选A。