Which type of fire extinguisher can be used on paper, wood, and flammable liquids?

The correct choice is foam. Foam fire extinguishers are specifically designed to tackle fires involving flammable liquids, as well as solid materials like paper and wood. The foam works by forming a barrier between the fuel and the oxygen in the air, effectively smothering the fire and cooling down the burning materials. This dual capability makes foam extinguishers versatile for a range of fire types, particularly in settings where both solids and liquids might be involved.

Water extinguishers are primarily effective on solid combustibles like wood and paper but should not be used on flammable liquid fires, as they can spread the fire further. CO2 extinguishers, while effective for electrical fires and some flammable liquids, do not work on solid materials like paper and wood. Wet chemical extinguishers are specially designed for cooking oils and fats, and they are not appropriate for general combustible fires involving paper or wood.