The doctor came up and asked me the day before.
A. what had I eaten
B. what I have eaten
C. what have I eaten
D. what I had eaten
网友回答
A. what had I eaten
B. what I have eaten
C. what have I eaten
(答案→)D. what I had eaten
解析：：考察宾语从句的语序。所有的名词性从句都使用陈述语序，排除AC。共计时态可知使用过去完成时。句意：医生走过来问我：前天吃了什么东西。故D正确。