The correct answer is option C) Hepato-pancreatic duct.

Explanation:
The bile duct and the pancreatic duct both play important roles in the digestive system. They are connected to the liver and the pancreas, respectively, and their main function is to transport digestive enzymes and substances into the duodenum, which is the first part of the small intestine.

The bile duct is responsible for carrying bile, a substance produced by the liver that aids in the digestion and absorption of fats. The pancreatic duct, on the other hand, transports pancreatic juice, which contains digestive enzymes that help break down carbohydrates, proteins, and fats.

When these two ducts reach the duodenum, they join together and form a common channel called the hepato-pancreatic duct, also known as the ampulla of Vater. This convergence of the bile and pancreatic ducts allows for the simultaneous release of bile and pancreatic enzymes into the duodenum, where they can effectively aid in the digestion of food.

The hepato-pancreatic duct opens into the duodenum through a small opening called the major duodenal papilla. This opening is located on the inner wall of the duodenum, near the junction with the stomach. The sphincter of Oddi, a ring of muscles surrounding the major duodenal papilla, controls the release of bile and pancreatic enzymes into the duodenum.

In summary, the bile duct and the pancreatic duct join together to form the hepato-pancreatic duct, which opens into the duodenum through the major duodenal papilla. This arrangement allows for the coordinated release of bile and pancreatic enzymes into the duodenum, facilitating the digestion and absorption of nutrients.

The bile duct and the pancreatic duct open together into the duodenum as the common hepato-pancreatic duct which is guarded by a sphincter called the sphincter of Oddi....