When two vessels are in immediate danger of collision，the stand-on vessel must（）.

A.Red flares or red rockets
B.Continuous sounding of fog signaling apparatus
C.International Code Flags November and Charlie
D.Basket hanging in the rigging

A.A continuous sounding of the fog horn
B.Firing a gun every minute
C.Five or more short rapid blasts on the whistle
D.A square flag and ball flown from the mast

A.forty two months from the date of manufacture
B.thirty six months from the date of the last inspection
C.twenty four months from the date of approval
D.twelve months from the date of purchase