单项选择题
A.power-driven vessel following a traffic lane B.pilot vessel enroute to a pilot station C.law enforcement vessel D.All of the above
A.stand-on vessel and would sound two short blasts B.give-way vessel and would sound no whistle signal C.stand-on vessel and would sound no whistle signal D.give-way vessel and would sound two prolonged blasts followed by two short blasts
A.two all-round red lights in a vertical line B.two yellow towing lights in a vertical line C.two white masthead lights in a vertical line D.two lights on the stern，one yellow and one white