Every vessel that is to keep out of the way of another vessel must take positive early action to comply with this obligation and must（）.

Every vessel that is to keep out of the way of another vessel must take positive early action to comply with this obligation and must（）.
A.avoid crossing ahead of the other vessel
B.avoid passing astern of the other vessel
C.sound one prolonged blast to indicate compliance
D.alter course to port for a vessel on her port side
正确答案：avoid crossing ahead of the other vessel