How does an inert gas system on a tanker function to prevent explosions in cargo tanks?

A
De-energizes the "charged mist" effect.
B
Maintains a positive pressure on the vent header to cool the flammable vapors.
C
Inert gas filters out the flammable vapors from the cargo tank spaces.
D
Inert gas dilutes the flammable vapor and air concentrations to keep them below the lower explosive limit.
E