Introducing inert gas into a tank already inert with the object of further reducing the oxygen or hydrocarbon content to prevent combustion if air enters the tank is called __________.

Correct Answer: Option A — purging

Purging involves injecting inert gas into a tank that is already in an inert condition to further depress oxygen or hydrocarbon gas concentrations. This safety margin ensures that subsequent operations or minor air ingress cannot create a flammable atmosphere.