Our food is almost __.We must ask for some help.该选什么?为什么?

题目

Our food is almost __.We must ask for some help.该选什么?为什么?
A.at the end B.at an end C.by the end D.in the end 并请详细解释它们之间的用法,

答案

选B
at an end 结束,终止;耗尽
at the end 在……的末尾
by the end 到……的末尾 常跟of连用
in the end 最终