What action does a pump perform to the water used to attack a fire?

The pump's primary function in firefighting is to pressurize the water used to attack a fire. This pressurization is essential because it enables the water to be effectively delivered through hoses and nozzles, allowing for a greater reach and increased force when spraying water on the fire. By increasing water pressure, the pump ensures that the water can penetrate the burning materials and reach deep into the flames, enhancing the efficiency of fire suppression efforts.

While the other actions referenced in the choices can be related to water or fire protection in broader contexts, they do not accurately describe the primary role of the pump in this specific scenario. Cooling, for instance, is a secondary effect of applying water to a fire, but it does not capture the function performed by the pump. Likewise, filtering and simply pumping do not address the critical aspect of pressure that is vital for effective fire suppression. Therefore, pressurization is the key action that supports firefighting operations.