The reaction between oils, fats, and dry chemical agents is called __________.

The correct response refers to saponification, which is a chemical reaction that occurs when oils or fats react with an alkali, often as part of a process to create soap. During saponification, triglycerides (which make up fats and oils) break down and combine with a base, resulting in the formation of glycerol and soap (the fatty acid salt). This process is essential to understand in fire investigations because it highlights how certain organic materials can react under specific conditions, notably in situations where fats or oils may be involved in a fire scenario.

Understanding saponification is important for fire investigators as it can affect the behavior of the fire and the materials involved, especially when they examine residues left after combustion. This reaction is distinct from the other processes listed, which involve different chemical transitions not specifically tied to the combination of oils, fats, and dry chemical agents.