请选择ABC,_.K*n']+A+b-m+\ My mother _______ three shelves.3o1{+J2D6Y7^.t:g-Y
A. have3o1{+J2D6Y7^.t:g-Y
B. has3o1{+J2D6Y7^.t:g-Y
C. is3o1{+J2D6Y7^.t:g-Y