**Core Concept**
A Meckel's diverticulum is a congenital anomaly of the small intestine, resulting from the incomplete closure of the vitelline duct during embryonic development. This leads to a small, pouch-like structure protruding from the antimesenteric border of the ileum.

**Why the Correct Answer is Right**
The most common location for a Meckel's diverticulum is the ileum, specifically within 60 cm of the ileocecal junction. This is because the vitelline duct usually obliterates during the 6th to 8th week of gestation, and the remaining tissue is more likely to form a diverticulum in this area. The antimesenteric border of the ileum is the most common site due to the embryological origin of the vitelline duct.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Meckel's diverticulum does not typically occur in the jejunum, which is the proximal part of the small intestine.

**Option B:** This option is incorrect because Meckel's diverticulum is not commonly associated with the colon, which is the large intestine.

**Option D:** This option is incorrect because Meckel's diverticulum is not typically located in the duodenum, which is the first part of the small intestine.

**Clinical Pearl / High-Yield Fact**
Meckel's diverticulum can contain ectopic gastric or pancreatic tissue, leading to complications such as gastrointestinal bleeding or obstruction. It is essential to consider this diagnosis in patients presenting with abdominal pain, bleeding, or obstruction.

**Correct Answer:** C.