如何理解 As you told me

问题描述

______ you told me, I had no idea of it.  

A. Until  B. When  C. While  D. As

答案为 D。请问怎么理解，答案对么？谢谢！ 

老师答疑

王老师：

此题答案不能是 D，而应是 A。
Until you told me, I had no idea of it.

句子意思：直到你告诉我，我才知道此事。

Until you told me I had no idea of it.
=I had no idea of it until you told me.

=I didn’t have any idea of it until you told me. 

=Not until you told me did I have any idea of it.