**Core Concept**
Putrefaction is a post-mortem process involving the breakdown of tissues, particularly proteins and fats, by bacteria. This process is influenced by various factors, including the environment, temperature, and the organ's blood supply.

**Why the Correct Answer is Right**
The liver is a highly vascular organ with a rich blood supply, which facilitates the growth of bacteria and the breakdown of tissues. As a result, putrefaction in the liver occurs relatively early after death. In contrast, the brain, being a solid organ with minimal blood supply, is more resistant to bacterial growth and putrefaction.

**Why Each Wrong Option is Incorrect**
**Option A:** The stomach is not typically associated with late putrefaction, as it has a rich blood supply and is prone to rapid decomposition.
**Option B:** The small intestine is also not characterized by late putrefaction, as it has a rich blood supply and is a common site for bacterial growth.
**Option C:** While the spleen is a solid organ with minimal blood supply, it is not typically associated with late putrefaction, as it is not as resistant to bacterial growth as the brain.

**Clinical Pearl / High-Yield Fact**
The brain is the last organ to undergo putrefaction due to its low blood supply and high concentration of myelin, which inhibits bacterial growth.

**Correct Answer: C. The brain is the last organ to undergo putrefaction due to its low blood supply and high concentration of myelin, which inhibits bacterial growth.**