A pressurized water extinguisher would be chosen to extinguish a

• A. Class B
• B. Class A
• C. Class D
• D. Class C

Answer: (B)

The main idea is that pressurized water extinguishers are designed to remove heat from fires involving ordinary combustibles. They work by cooling the fuel below its ignition temperature, which stops the combustion process. That makes them ideal for fires with materials like wood, paper, and textiles. They should not be used on fires involving flammable liquids because the water would spread the liquid and worsen the fire, on electrical fires due to the risk of electric shock or short circuits, or on metal fires because many metals react with water and can intensify the hazard. So, the best fit is fires with ordinary combustibles.