Which of the following completes the fire triangle?

• A. Combustible material; oxygen; ignition source
• B. Fuel; oxygen; heat
• C. Oxygen; heat; fuel
• D. Water; air; spark

Answer: (A)

Fire cannot start or continue without three elements: a fuel source, heat, and an oxidizer (usually oxygen). The option that fits best uses common safety terminology for these elements: combustible material for the fuel, oxygen for the oxidizer, and ignition source for the heat input that starts combustion. Together, these three components—the combustible material, the oxygen, and the ignition source—complete the fire triangle. The other choices either introduce something not part of the triangle (like water) or mix the same three elements in less direct wording. So the combination that aligns with standard safety language is the one that identifies combustible material, oxygen, and ignition source.