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: Surgery
[{'content': 'A male aged 60 years has foul breath. He regurgitates food that is eaten 3 days ago : Likely diagnosis is ? \nSelect and explain. \nA. Zenkers diveiculum, B. Meckels diveiculum, C. Scleroderma, D. Achalasia cardia', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Zenker's diveiculum", 'role': 'assistant'}]