After extinguishers expended, and if possible, the ______ supply to the space should be secured.

• A. Ventilation
• B. Fuel
• C. Electrical
• D. Lighting

Answer: (A)

Controlling the air flow in a space after using extinguishers is crucial. Securing the ventilation supply helps limit how much fresh air can reach the area, slowing or stopping the fire’s ability to re-ignite and preventing smoke and toxic gases from spreading to other parts of the vessel. When extinguishers have been expended, the priority is to contain the environment around the fire so responders can work safely and assess remaining hazards. Other supplies like fuel or electrical might be addressed, but ventilation control directly reduces the fire’s oxygen supply and smoke movement, making it the best action in this situation.