Which class of fire must be extinguished using special agents due to the risk of explosion?

The correct answer is associated with Class C fires, which involve energized electrical equipment. Using water or standard extinguishing agents on these types of fires can create a significant risk of electrical shock or explosion. This is because the use of water can conduct electricity, putting the individual extinguishing the fire in danger and potentially causing further damage if the electrical system is involved.

In contrast, Class D fires involve combustible metals, which require special dry powder agents designed specifically for such materials. Class A fires involve ordinary combustibles such as woods and papers, typically extinguished using water or foam. Class B fires are fueled by flammable liquids, which can be managed with foam, dry chemicals, or CO2, though they don't have the same risk associated with electrical hazards. Understanding the specific nature of each class of fire is crucial for choosing the appropriate extinguishing agent while ensuring safety during firefighting efforts.