Which type of fire extinguisher can be used to safely extinguish a paper fire?

The type of fire extinguisher that can be used to safely extinguish a paper fire is the Class A fire extinguisher. Class A extinguishers are specifically designed for use on ordinary combustible materials, which include paper, wood, cloth, and certain plastics. They work by using water or other extinguishing agents that effectively cool and suffocate the fire, eliminating the heat element necessary for combustion.

In contrast, Class B extinguishers are meant for flammable liquids such as gasoline and oil, Class C extinguishers are intended for electrical fires, and Class D extinguishers are designed for combustible metals. Each of these classes uses different agents and methods suitable for their specific materials, but they would not effectively handle a fire involving paper. Therefore, for a paper fire, the Class A extinguisher is the appropriate choice due to its compatibility with ordinary combustibles.