Final answer:
The primary factor influencing the burning of fire in a room is oxygen concentration, as it is essential for the chemical processes that occur during a fire.
Step-by-step explanation:
The primary factor influencing the burning of fire in a room among the options provided would be D) Oxygen concentration. According to Smokeybear.com, the three elements needed for a fire to occur are heat, fuel, and oxygen. Oxygen is crucial for the chemical processes that occur during a fire, specifically it supports oxidation. This reaction with fuel releases heat and generates combustion products. Ambient temperature, wind direction, and fuel type do impact fire behavior but without sufficient oxygen concentration, a fire cannot sustain.