If a fire ignites in the engine room as a result of a high-pressure fuel oil leak, you should FIRST __________.

Correct Answer: Option D — shut off the fuel oil supply

Eliminating the fuel source is the primary objective in any Class B fire. Per standard marine firefighting procedures, stopping the flow of pressurized fuel prevents the fire from being continuously fed, which is essential before attempting to extinguish the flames with portable equipment or fixed systems.