This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
[{'content': 'Commonest site of peptic ulcer is: \nSelect and explain. \nA. 1st part of duodenum, B. 2nd part of duodenum, C. Distal 1/3rd of stomach, D. Pylorus of the stomach', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) 1st part of duodenumRef: Sabiston 19th Edition, Page 1199* Most common location 1st part of duodenum* Most common location in stomach is incisura angularis', 'role': 'assistant'}]