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

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

Eliminating the fuel source is the primary objective in a Class B fire. Shutting off the fuel oil supply stops the flow of flammable liquid, effectively starving the fire. Once the fuel is secured, the crew can then address ventilation and suppression using appropriate firefighting agents like CO2 or foam.