What type of fire involves combustible metals?

The correct choice is Class D Fire, which specifically pertains to fires that involve combustible metals. These types of fires are distinct from other classes of fires due to the unique characteristics of the metals involved, such as magnesium, titanium, sodium, and potassium. Class D fires require special extinguishing methods; typical water-based extinguishers or foam agents can react violently with these metals. Instead, dry powder extinguishing agents that smother and cool the burning metal are needed.

Understanding the classification of fires is critical for safety and effective firefighting. Each class of fire has specific characteristics and appropriate extinguishing methods, making it essential for firefighters to properly identify the fire type in emergency situations.