What is the name given to the chemical reaction in which oxygen combines with another substance?

The correct answer is oxidation. In chemistry, oxidation refers to the process where a substance reacts with oxygen, leading to a loss of electrons or an increase in oxidation state. This reaction is fundamental in various biological and chemical processes, including combustion and respiration.

Oxidation is often accompanied by the release of energy, which is why it plays a crucial role in generating energy for living organisms. The significance of this process extends to many industries, including the management of materials and environmental health, where understanding how oxidation affects substances can be essential.

In contrast, reduction is a process that involves the gain of electrons or a decrease in oxidation state, usually occurring alongside oxidation in a complementary reaction. Hydrolysis refers to the chemical breakdown of a compound due to reaction with water, and saturation pertains to the extent to which a substance can dissolve in a solvent. Thus, the specific nature of oxidation as a reaction involving oxygen makes it the correct choice in this context.