为自己加油

"In hydraulic system, a single EMDP powers the standby system which is available when required to operate the rudder, thrust reversers and extend the leading edge flaps and slats." In the above sentence, which component is not mentioned?

A.方向舵;;
B.反推力装置;
C.前缘襟翼和缝翼
D.扰流板;