Final answer:
The fire extinguishing method that works by excluding oxygen from the burning process is smothering. It involves applying a barrier over the fire to block oxygen, which is essential for combustion.
Step-by-step explanation:
The method of extinguishing that works by excluding oxygen from the burning process is known as smothering. When a fire is smothered, a material such as foam, sand, or a chemical fire suppressant is applied over the fire to create a barrier between the fuel and the oxygen in the air. This barrier prevents the fire from continuing to burn due to a lack of oxygen, which is one of the essential components of the fire triangle (fuel, heat, and oxygen).
In the context of the specific methods of fire extinguishing listed in the question, here are the definitions:
- Cooling - Lowers the temperature of the burning material below its ignition point.
- Smothering - Excludes oxygen from the fire.
- Saponification - Involves the chemical transformation of fats into soap and alcohol in the presence of strong alkali, which then acts as a fire suppressant. It's particularly effective on kitchen fires involving cooking oils and fats.
- Chain breaking - Chemical agents interrupt the chain reaction occurring in the combustion process.
Therefore, the correct answer to which method of extinguishing works by excluding oxygen from the burning process is B. Smothering.