This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Brunners glands are seen in ? 
Select and explain. 
A. Jejunum, B. Upper duodenum, C. Lower duodenum, D. Appendix
B: Upper duodenum
Answer: B: Upper duodenum 
Explanation: Upper duodenumThe presence of mucous duodenal (Brunner's) glands in the submucosa is indicative of upper duodenum. These submucosal glands are absent in the jejunum, ileum and the entire large intestine.