单项选择题

A.hand_put(y_gj,wz1);delay_ms(200);hand_pick(y_gj,wz1);
B.hand_pick(y_gj,wz1);delay-ms(200);hand_put(y_gj,wz1);
C.hand_put(c_gj,wz1);delay_ms(200);hand_pick(c_gj,wz1);
D.hand_pick(c_gj,wz1);delay_ms(200);hand_put(c_gj,wz1);