请选择CBA1y8W(y;|(_:O+}5t5~7jMrs. Sun is a friend of _______.9m9S/R.h2{3Q.U
A. Mary's mother9m9S/R.h2{3Q.U
B. mother of Mary9m9S/R.h2{3Q.U
C. Mary 's mother's9m9S/R.h2{3Q.U