The abbreviation "GM" is used to represent the （）

A.all ballast is processed through the oily water separator
B.ballast is taken on and discharged through a separate main deck riser
C.ballast and cargo tanks are separated by cofferdams
D.all ballast lines, tanks, and pumps are independent of those used for oil

A.discharge of ballast or cleaning water from fuel tanks
B.sounding levels of all fuel tanks on a daily basis
C.grade and specific gravity of all fuel oil carded
D.fuel consumption rates on a weekly basis

A.the oil content in water
B.the water content in fuel oil
C.the water level in bilge well
D.the oil level in bilge well