What is the method used for a pool of flammable product on open ground called?

The correct answer pertains to the "Roll on method," which is a technique used to combat fires involving pools of flammable liquids on open ground. In this method, a fire-suppressing agent, often foam or an appropriate extinguishing agent, is rolled onto the surface of the burning material. The rolling action helps to spread the agent uniformly across the burning liquid, effectively smothering the flames and minimizing the risk of flare-ups. This technique is particularly useful for controlling surface fires and providing a barrier between the fuel and the ignition source.

In contrast, the other methods listed involve different techniques for fire suppression that may not be as effective with burning pools of flammable liquids. For example, the spray method usually employs a fine mist to reduce heat and disperse vapors, which may not be sufficient for direct flame suppression in liquid pools. The flood method generally involves applying water in large quantities, which can be ineffective and hazardous when dealing with flammable liquids, as it can spread the fire further. The pour method typically refers to pouring a liquid agent directly onto a fire, which can be less controlled and potentially exacerbate the situation, especially with flammable liquids. Thus, the effectiveness and appropriateness of the roll on method make it the correct choice