【单选题】Your vessel has a gasoline engine and a mechanical exhaust ventilation system.BEFORE starting the engine,the exhaust blower should be run long enough to ______.
A.
warm up the exhaust blower motor
B.
provide a proper supply of fresh air for the engine(s)
C.
see the system is in good operating condition
D.
insure at least one complete change of air in the compartments concerned