Which of the following are parts of the fire tetrahedron?

The fire tetrahedron is a model used to understand the four essential components needed for a fire to ignite and sustain itself. These components are heat, oxygen, fuel, and a chain reaction.

Heat is required to raise the material to its ignition temperature, oxygen supports the combustion process, and fuel is the material that burns. The chain reaction refers to the self-sustaining process of combustion where the products of combustion provide heat, perpetuating the fire.

In the correct option, each of these elements is represented accurately. While other options might include some related concepts, they mix up the critical components or introduce elements that are not part of the fire tetrahedron, such as water or smoke, which do not contribute to sustaining a fire and can actually extinguish it under certain conditions. Understanding the fire tetrahedron is critical for effective firefighting strategies and the prevention of fire incidents.