**Core Concept**
G-cells are a type of neuroendocrine cell found in the gastrointestinal tract, responsible for producing gastrin, a hormone that stimulates gastric acid secretion. The presence and distribution of G-cells are crucial for understanding normal gastric function and the pathophysiology of various gastrointestinal disorders.

**Why the Correct Answer is Right**
G-cells are predominantly located in the pyloric antrum, a region of the stomach near the pyloric sphincter. This specific localization allows for the precise regulation of gastric acid secretion, which is essential for the digestion and absorption of nutrients. The high concentration of G-cells in the pyloric antrum enables the stomach to adapt to various dietary inputs and maintain a balanced gastric environment.

**Why Each Wrong Option is Incorrect**
**Option A:** The fundus of the stomach primarily contains parietal cells, which are responsible for the production of gastric acid, not G-cells.
**Option B:** The cardia of the stomach is the region that connects the esophagus to the stomach and does not contain a significant number of G-cells.
**Option D:** The body of the stomach does contain some G-cells, but they are not as densely concentrated as in the pyloric antrum.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the distribution of G-cells in the stomach is not uniform, and their presence can be influenced by various factors, including age, diet, and gastrointestinal disorders. Understanding the localization of G-cells can aid in the diagnosis and management of conditions such as Zollinger-Ellison syndrome, which is characterized by excessive gastrin production and gastric acid hypersecretion.

**✓ Correct Answer: C. Pyloric antrum**