What type of extinguishing method is primarily used with water?

The method primarily used with water for extinguishing fires is cooling. Water is applied to a fire primarily to remove heat, which is one of the essential elements of the fire triangle (fuel, heat, and oxygen). When water is sprayed or poured on a fire, it absorbs the heat from the flames and the surrounding materials, lowering the temperature to a point where combustion cannot be sustained. This cooling effect effectively reduces the fire's ability to continue burning.

Moreover, water can turn into steam when it is heated, which also helps in displacing some of the oxygen around the fire, but the primary action is its ability to reduce overall temperature.

While chemical conversion refers to the alteration of the fuel's chemical composition, and oxygen displacement involves preventing the combustion process by removing oxygen, these methods are not the primary functions of water as an extinguishing agent. Therefore, cooling is the correct answer in this context.