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 diverticulum, B. Meckels diverticulum, C. Scleroderma, D. Achalasia cardia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]