What is a major factor in determining the temperature of a fire?

The correct choice revolves around the concept of combustion, where oxygen plays a crucial role in determining the temperature of a fire. Without an adequate supply of oxygen, a fire cannot sustain itself or reach high temperatures. The combustion process requires both fuel and oxygen to ignite and maintain a flame; however, it is the oxygen that significantly influences how hot the fire burns. In scenarios where oxygen is plentiful, fires will burn hotter and more efficiently due to the enhanced reaction between the fuel and the oxygen. Conversely, limited oxygen availability can lead to cooler fires or smoldering conditions, highlighting its importance in the dynamics of fire temperature.

While the amount of fuel available can affect fire size and duration, and humidity levels may influence how easily materials ignite, it is the availability of oxygen that directly affects the intensity and temperature of the fire.