**Core Concept**
The most common congenital anomaly of the pancreas is pancreatic hypoplasia, which refers to a reduction in the size or number of pancreatic islets or acinar cells. This anomaly can lead to pancreatic insufficiency and increased susceptibility to pancreatitis.

**Why the Correct Answer is Right**
Pancreatic hypoplasia occurs due to a failure of pancreatic bud formation during embryonic development. The pancreatic bud is a critical structure that gives rise to the pancreas, and abnormalities in its development can lead to various congenital anomalies. Pancreatic hypoplasia is often associated with other congenital anomalies, such as duodenal atresia or stenosis.

**Why Each Wrong Option is Incorrect**
**Option A:** Pancreatic divisum is a congenital anomaly where the pancreatic duct does not properly develop, but it is not the most common anomaly. Instead, it is a relatively common cause of pancreatitis.
**Option B:** Annular pancreas is a rare congenital anomaly where pancreatic tissue surrounds the second part of the duodenum, but it is not the most common anomaly.
**Option C:** Pancreatic agenesis is a rare congenital anomaly where the pancreas is completely absent, but it is not the most common anomaly.

**Clinical Pearl / High-Yield Fact**
Pancreatic hypoplasia is often associated with other congenital anomalies, making a careful evaluation of the patient's overall anatomy and clinical presentation essential for diagnosis and management.

**Correct Answer: C. Pancreatic hypoplasia**