单项选择题

A.空船状态(Ba/L•d=1.8)时,Ⅴy=1/20•Ⅴa;(Ⅴa为风速)
B.满载状态(Ba/L•d=0.8)时,Ⅴy=1/50•Ⅴa
C.空载状态(Ba/L•d=1.8)时,Ⅴy=1/30•Ⅴa
D.空载状态(Ba/L•d=0.8)时,Ⅴy=1/50•Ⅴa