What are the four basic elements of Fire?

A.
Heat, Fuel, Oxygen, and Chain Reaction

B.
Heat, Fuel, CO2, and Chain Reaction

C.
Heat, Wood, Oxygen, and Chain Reaction

D.
Flame, Fuel, Oxygen, and Chain Reaction

Explanation:
The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most
fires.
The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually
oxygen). A fire naturally occurs when the elements are present and combined in the right mixture, meaning that
fire is actually an event rather than a thing. A fire can be prevented or extinguished by removing any one of the
elements in the fire triangle. For example, covering a fire with a fire blanket removes the oxygen part of the
triangle and can extinguish a fire.
The fire tetrahedron represents the addition of a component, the chemical chain reaction, to the three already
present in the fire triangle. Once a fire has started, the resulting exothermic chain reaction sustains the fire and
allows it to continue until or unless at least one of the elements of the fire is blocked. Foam can be used to deny
the fire the oxygen it needs. Water can be used to lower the temperature of the fuel below the ignition point or
to remove or disperse the fuel. Halon can be used to remove free radicals and create a barrier of inert gas in a
direct attack on the chemical reaction responsible for the fire.
Incorrect Answers:
B: CO2 is not one of the four basic elements of fire. CO2 is a fire suppressant. Therefore, this answer is
incorrect.
C: Wood is not one of the four basic elements of fire. Wood would be an example of the ‘fuel’ element of fire.
Therefore, this answer is incorrect.
D: Flame is not one of the four basic elements of fire. Flame is just another name for fire. Therefore, this
answer is incorrect.

https://en.wikipedia.org/wiki/Fire_triangle