20.依國際海上避碰規則，當你看見他船顯示「three all-round lights in a vertical line, the highestand the lowest of these lights are red and the middle light is white」，表示該船為：
(A)A vessel is not under command.
(B)A vessel restricted in her ability to manoeuver.
(C)Fishing boat under way.
(D)A pilot vessel is not engaged on pilotage duty.