i'm sorry i___it __yours.a.didn't know;was b.didn't know; is

i'm sorry i___it __yours.a.didn't know;was b.didn't know; is
i'm sorry i___it __yours.a.didn't know;was b.didn't know; is

i'm sorry i___it __yours.a.didn't know;was b.didn't know; is
结合意境是B了,选A的话意思就变成了 东西之前是你的,现在不是了,was 是过去曾经的,