Unless such oil tanker carries crude oil which is not suitable for crude oil washing，the oil tanker shall（）the system in accordance with the requirements of that Regulation.

A.flammable vapors from entering machinery space
B.flue gas escaping to atmosphere
C.inert gas escaping to atmosphere
D.air entering inert gas system

A.allow sufficient oxygen in the tank to sustain life
B.prevent outside air from entering the tank
C.provide more discharge pressure
D.comply with pollution regulations

A.displayed in at least 4 different positions on the barge
B.carved on a wooden board and attached to the barge's hull
C.displayed as close to the navigation lights as possible
D.displayed at the highest point of the barge's hull such that it can be seen from either side