Which of the following is a post-hepatic cause of obstructive jaundice?

Choledocholithiasis, or the presence of gallstones in the common bile duct, is a post-hepatic cause of obstructive jaundice because it obstructs the normal flow of bile from the liver and gallbladder to the intestine. When the flow of bile is blocked due to this obstruction, bilirubin, which is a byproduct of the breakdown of red blood cells, cannot be properly excreted from the body. As a result, it accumulates in the bloodstream, leading to jaundice.

In contrast, hepatitis, cirrhosis, and alcoholic liver disease are primarily intrahepatic causes. They involve issues within the liver itself, such as inflammation (hepatitis), scarring of liver tissue (cirrhosis), or damage due to alcohol consumption (alcoholic liver disease). These conditions may lead to difficulties in bilirubin metabolism but do not typically cause a mechanical blockage of bile flow, which is necessary for categorizing a condition as post-hepatic obstructive jaundice. Therefore, choledocholithiasis distinctly fits the criteria for post-hepatic causes.