**Core Concept**
The gallbladder is a small organ that stores bile, a digestive fluid produced by the liver. A common condition affecting the gallbladder is the formation of gallstones, which are solid particles that can block the flow of bile. A common type of gallstone is the cholesterol gallstone, which forms in the gallbladder when bile contains too much cholesterol.

**Why the Correct Answer is Right**
The correct answer is not a feature of a common bile duct (CBD) stone. CBD stones are typically formed in the bile ducts and are often composed of bilirubin, cholesterol, and other substances. They form when there is an imbalance in the composition of bile, leading to the precipitation of these substances. A key feature of CBD stones is that they can cause obstructive jaundice, which is a condition characterized by the yellowing of the skin and eyes due to the buildup of bilirubin in the blood.

**Why Each Wrong Option is Incorrect**
**Option A:** A feature of CBD stones is that they can cause pancreatitis, which is inflammation of the pancreas. This is because the blockage of the bile duct can cause bile to flow back into the pancreas, leading to inflammation. While this is a complication of CBD stones, it is not a feature that distinguishes them from other types of gallstones.

**Option B:** Another feature of CBD stones is that they can cause cholangitis, which is an infection of the bile duct. This occurs when bacteria enter the bile duct through a stone or other blockage, leading to infection. While this is a serious complication of CBD stones, it is not a feature that distinguishes them from other types of gallstones.

**Option C:** A feature of CBD stones is that they can cause abdominal pain, which is a common symptom of gallstone disease. However, this is not a feature that distinguishes CBD stones from other types of gallstones, as abdominal pain can also be caused by other conditions.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that CBD stones are often diagnosed incidentally during imaging studies for other conditions, such as pancreatitis or abdominal pain. This is because the symptoms of CBD stones can be non-specific and are often similar to those of other conditions.

**Correct Answer: A.**