Sister sent me a picture of ________, which had been taken on the Great Wall.

A.Mother

B.my mother's

C.mother's

D.mother

答案及解析： A

解析：

巧解

分析：a picture of Mother my mother译为：妈妈的一张照片，指妈妈本人的照片。a picture of my mother's译为：妈妈的一张照片，但照片上不一定是妈妈本人。所以答案选A。