Tank vessel inerting refers to _________________.

A
the introduction of inert gas into a tank with the object of reducing the oxygen content to below 8% by volume
B
the introduction of inert gas into a gas free tank for the purpose of reducing the oxygen content to below 8% by volume
C
the introduction of inert gas into a cargo tank during cargo discharge to replace the volume of discharged cargo
D
All of the above
E