What class of fire involves wood and paper and typically uses which type of extinguishing agent?

The correct choice emphasizes that Class A fires, which involve ordinary combustibles such as wood and paper, are most effectively extinguished using water-based agents, multipurpose dry chemicals, and specific dry chemical agents designed for Class A fires. Water is particularly effective because it cools the burning material and reduces the temperature below its ignition point, thus stopping the combustion process. Multipurpose dry chemicals can also be effective since they interrupt the chemical reactions occurring in the fire.

In contrast, carbon dioxide and halon (mentioned in other options) are more suited for Class B or C fires, which involve flammable liquids or electrical equipment, respectively. Foam is primarily designed for Class B fires, as it can smother and separate fuel from oxygen, which is not applicable to wood and paper. Thus, the focus on water-based and multipurpose agents in the correct answer highlights their role in addressing the combustion characteristics of Class A fire materials.