按照CDFA的下降剖面,可持续下降到距跑道头多少英尺高度?According to the descend path of CD

按照CDFA的下降剖面,可持续下降到距跑道头多少英尺高度?According to the descend path of CDFA,the aircraft can continuously descend to which height above the threshold?

A.15ft

B.35ft

C.50ft

正确答案是C