Which statement describes common portable extinguisher media and the primary fire classes they address?

• A. Water for Class A; Foam for Class A and B; Dry chemical for ABC; CO2 for B and C; Wet chemical for Class K.
• B. Water for Class A; Foam for Class C; Dry chemical for ABC; CO2 for B and C; Wet chemical for Class K.
• C. Water for Class B; Foam for Class A; Dry chemical for B; CO2 for A and C; Wet chemical for Class K.
• D. Water for Class A; Foam for Class A; Dry chemical for A; CO2 for B; Wet chemical for Class K.

Answer: (A)

This question tests knowing which extinguisher media are used for the common fire classes and why each pairing makes sense in practice. Water is used for Class A fires because it cools the burning ordinary combustibles (like wood, paper, cloth) and lowers the heat to stop the burning process. Foam is suitable for Class A and B fires because it creates a stabilizing blanket that cools solids and also forms a barrier between the fuel and the air, helping to smother liquid fires. Dry chemical extinguishers labeled ABC are multipurpose, capable of handling A, B, and C fires by coating the fuel, smothering the fire, and interrupting chemical reactions. CO2 extinguishers work well on Class B and C fires by displacing the oxygen and cooling in some cases, which makes them effective for liquids and electrical fires but not ideal for ordinary combustibles. Wet chemical extinguishers are designed specifically for Class K (cooking oil) fires and use saponification to form a soapy layer that cools and separates fats/oils from the flame.

The best-matching statement assigns water to Class A, foam to A and B, dry chemical to ABC, CO2 to B and C, and wet chemical to Class K. That alignment reflects how each media behaves with its target fuels and fire environments.