The ALTERNATE FLAPS Master Switch:
A.A.Fully extends the LE Devices using Standby Hydraulic pressure, and electrically extends the TE Flaps
B.B.Closes the Flight Spoiler Shutoff valve
C.C.Activates the Standby Hydraulic Pump and pressurizes the STANDBY Rudder Power Control Unit
D.D.Arms the Alternate Flaps Position Switch, activates the Standby Hydraulic Pump, and closes the Trailing
正确答案是D