Which of the following is a common cause of combustion failure?

Insufficient oxygen is a common cause of combustion failure because combustion is a chemical reaction that requires three key elements: fuel, heat, and an oxidizing agent—in most cases, oxygen. When the supply of oxygen is limited, the reaction cannot sustain itself, leading to incomplete combustion or failure to ignite altogether.

In a fire scenario, if there isn’t enough oxygen, the fire will struggle to reach the necessary temperature for combustion to occur. This results in smoke and dangerous gases being produced, rather than flames. Inadequate oxygen often occurs in confined spaces or areas where ventilation is poor, making it a critical factor in promoting or sustaining fire conditions.

Other options like lack of fuel, excessive temperature, and poor ventilation, can greatly affect the combustion process but do not directly highlight the fundamental requirement for oxygen that sustains combustion.