The correct option is A Bile
Ductus choledochus, also known as the common bile duct is the duct present in the gastrointestinal tract. It is formed by the union of the cystic duct and the hepatic duct. Its function is to carry bile from the liver and the gallbladder to the duodenum. Hence conduction of bile is the main function of the Ductus choledochus. Thus the correct answer is option A.