What factors affect fire behavior?

The correct choice identifies crucial factors that directly influence how fires ignite, spread, and behave.

Fuel type is significant because different materials burn at different rates and temperatures, which affects the intensity and duration of the fire. For example, wood ignites and burns differently from synthetic materials. Temperature is another critical factor, as it impacts the rate of combustion; higher temperatures can lead to faster flaming and increased fire spread. Oxygen levels are essential as fires need an adequate supply of oxygen to sustain combustion; limited oxygen can suppress fire growth. Lastly, environmental conditions, like wind speed and terrain, can significantly influence fire behavior by altering how the fire spreads and evolves.

In contrast, the other choices include factors such as firefighter training and equipment age, which, while important in managing fires effectively, do not directly affect the physical behavior of fire itself. Additionally, elements like water content and fire extinguisher type relate more to fire suppression rather than fire dynamics.