The operation sequence of the line power outage is ( ).

A、First break the bus QS, then break the line QS, finally the Q
F、;
B、First break the line QS, then break the bus QS, finally the Q
F、;
C、First break the QF, then break the line QS, finally the bus QS.;
D、First break the QF, then break the bus QS, finally the line QS.