Which of the fire extinguishing agents listed can be used to effectively combat a class B fire?

Correct Answer: Option D — All of the above

Class B fires involve flammable liquids, gases, or greases. Effective suppression requires smothering the fire to remove oxygen. Dry chemical, foam, and CO2 are all approved agents for Class B fires, as they either interrupt the chemical chain reaction or displace oxygen to extinguish the fuel source.