What is the process of something putrefying?

The process of putrefaction refers specifically to the decomposition of organic matter, where bacteria and other microorganisms break down the material, resulting in decay. This degradation often produces unpleasant odors due to the release of gases and byproducts from the breakdown process. The term "putrefy" is closely associated with the rotting of organic substances, such as food or dead plants and animals, which aligns perfectly with the description provided in the correct answer.

In contrast, the other options describe processes that are either beneficial or contrary to decay. Improving health, facilitating growth, and preserving freshness all involve positive transformations or maintenance of the state of matter, which do not relate to the concept of putrefaction. Therefore, the answer captures the essence of what occurs during putrefaction: a chemical change leading to decomposition and the resultant foul smell.