**Core Concept**
The formation of stones in the common bile duct (CBD) is a complex process involving the precipitation of cholesterol, bilirubin, and other substances. The main factors contributing to the development of CBD stones include biliary stasis, increased cholesterol secretion, and decreased bile salt secretion.

**Why the Correct Answer is Right**
The correct answer is not provided, so I will assume a common scenario. However, since the question is incomplete, I'll provide a general explanation for one common statement about CBD stones.

A common statement regarding CBD stones is: "The majority of stones in the common bile duct are cholesterol stones."

This statement is correct because cholesterol stones are the most common type of biliary stone, accounting for approximately 70-80% of cases. They form when there is an imbalance between the secretion of cholesterol and bile salts, leading to the precipitation of cholesterol crystals.

**Why Each Wrong Option is Incorrect**
Since the options are incomplete, I'll provide explanations for a hypothetical set of options.

* **Option A:** "CBD stones are always associated with gallstones."
This statement is incorrect because while many CBD stones originate from the gallbladder, some may form de novo in the CBD due to biliary stasis or other factors.
* **Option B:** "CBD stones are always symptomatic."
This statement is incorrect because some CBD stones may be asymptomatic, especially if they are small or do not cause significant obstruction.
* **Option C:** "CBD stones are always treated with surgical removal."
This statement is incorrect because many CBD stones can be treated with endoscopic retrograde cholangiopancreatography (ERCP) or other minimally invasive techniques.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the risk of developing CBD stones increases with age, especially after the age of 50. This is often due to the accumulation of cholesterol crystals and biliary stasis over time.

**Correct Answer: Not Provided**