Each main wheel is provided with a hydraulic actuated multidisc

Each main wheel is provided with a hydraulic actuated multidisc brake unit bolted to a flange on the axle.In the above sentence ,"a hydraulic actuated multidisc brake unit" means

A.一个多刹车盘装置

B.一个液压操纵的刹车盘装置

C.一个液压操纵的多刹车盘

D.一个液压操纵的多刹车盘装置

正确答案是D