_____ arriving home she found her old friend already there.

_____ arriving home she found her old friend already there.
A、On
B、For
C、By
D、With
【正确答案】：A
【题目解析】：本题考察介词辨析，句意为：她一到家就发现他的老朋友已经在那里了。On 一……就……，符合题意。for为了，by 通过，with 用。