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

Correct Answer: Option C — Inert gas dilutes the flammable vapor and air concentrations to keep them below the lower explosive limit.

Inert gas systems maintain an atmosphere within cargo tanks where the oxygen concentration is kept below the level required for combustion, typically below 8% by volume. By displacing oxygen with non-flammable flue gas, the mixture remains outside the flammable range, effectively preventing ignition regardless of the presence of flammable vapors.