单选题 I ______ to post the letter that I wrote to my parents, but I was too busy.
A) remembered C) had remembered
B) must remember D) should have remembered

A、 I ______ to post the letter that I wrote to my parents, but I was too busy.
B、 remembered
C、 must remember
D、 had remembered
E、 should have remembered

【正确答案】 D

【答案解析】