## Core Concept
The greater omentum is a significant fold of visceral peritoneum that hangs from the greater curvature of the stomach. It plays a crucial role in the abdominal cavity, including immune function and fat storage. Anatomically, it is known for its layered structure.

## Why the Correct Answer is Right
The greater omentum is composed of four layers of peritoneum: two layers that descend from the greater curvature of the stomach and the proximal part of the duodenum, and two layers that ascend to the transverse colon. These layers enclose the omental bursa (or lesser sac), which communicates with the rest of the peritoneal cavity through the epiploic foramen (of Winslow). The correct number of layers in the greater omentum is four.

## Why Each Wrong Option is Incorrect
- **Option A:** This option suggests an incorrect number of layers.
- **Option B:** This option also suggests an incorrect number of layers.
- **Option D:** Similarly, this option does not accurately represent the number of layers in the greater omentum.

## Clinical Pearl / High-Yield Fact
A key clinical point to remember is that the greater omentum can be used as a natural barrier or wrap to limit the spread of abdominal infections or to facilitate healing in certain surgical contexts. Its mobility and ability to fold over structures make it surgically significant.

## Correct Answer Line
**Correct Answer: C. Four.**