The steering oar in a lifeboat is usually referred to as the（）.

A.shorter than the others
B.used for the stroke oar
C.used by the forward man in the boat to direct the bow
D.longer than the others and should be lashed to the stern

A.is stated on the vessel's Certificate of Inspection
B.is the number authorized in the Navigation Rules
C.depends on the number of lifejackets you carry
D.is the number authorized by your license

A.when the power source is replaced
B.each year after installation
C.every six months
D.when it is no longer serviceable