"Who's knocking at the door?" "______ is Kate."

问题描述:

"Who's knocking at the door?" "______ is Kate."
A. itB. this C. heD. she
请高手给个确切的答案,再讲下其中的语法知识,谢谢!

选A
习惯用法,一般说It's me,表示“是我”的意思.It作人称代词时,可用来代替人、物或事.