Which classes of fire extinguishers are for combustible liquids?

The answer is based on the classification of fire extinguishers according to the types of fires they are designed to combat. Fire extinguishers are categorized into classes that correspond to specific fire hazards.

Class B fire extinguishers are specifically designed for fires involving combustible liquids, which include flammable liquids such as gasoline, oil, and paints. These extinguishers work by smothering the flames and preventing oxygen from fueling the fire, which is critical when dealing with liquids that can ignite easily and are difficult to extinguish with water.

The other classes of fire extinguishers do not address combustible liquids effectively. For example, Class A extinguishers are intended for ordinary combustible materials like wood or paper, Class C extinguishers are designed for fires involving energized electrical equipment, and Class D extinguishers are meant for fires involving combustible metals. Thus, Class B stands out as the appropriate choice for fires involving combustible liquids.