This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen and pelvis, Subject name: Anatomy
[{'content': '"Sub-mucosal glands" are present in? \nSelect and explain. \nA. Duodenum, B. Colon, C. Anal canal, D. Stomach', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Duodenum and oesophagus have submucosal glands. The submucosa of the duodenum is densely packed with mucous Brunner&;s glands.The oesophagus has occasional submucosal mucous glands.Reference: Chaurasia; 6th edition', 'role': 'assistant'}]