The correct answer is option 2: Duodenum. The duodenum is the first part of the small intestine, located immediately after the stomach. It is responsible for receiving the secretions of the liver and pancreas through a common duct called the hepatopancreatic duct.

Option 1: Stomach is incorrect. While the stomach does receive secretions from the specialized cells lining its walls, it does not receive secretions from the liver and pancreas through a common duct.

Option 2: Duodenum is correct. As mentioned above, the duodenum is the part of the small intestine that receives the secretions of the liver and pancreas through the hepatopancreatic duct.

Option 3: Junction of Jejunum and Ileum is not the correct answer. The junction of the jejunum and ileum is a site where the small intestine transitions from the jejunum to the ileum. It does not receive the secretions of the liver and pancreas.

Option 4: Ileum is not the correct answer. The ileum is the final part of the small intestine, and it does not receive secretions from the liver and pancreas through a common duct.

Overall, the duodenum is