请选择ABC+O7B7R4\,y,x+M0y7U2I-D5G:X;j What lessons do you have ______ the afternoon?/^6Z*M9P7`'T0[0i2T:`/`
A. in/^6Z*M9P7`'T0[0i2T:`/`
B. on/^6Z*M9P7`'T0[0i2T:`/`
C. at/^6Z*M9P7`'T0[0i2T:`/`