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
"Sub-mucosal glands" are present in? 
Select and explain. 
A. Duodenum, B. Colon, C. Anal canal, D. Stomach
A: Duodenum
Answer: A: Duodenum 
Explanation: 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