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': "Meckel's diverticulum is remnant of \nSelect and explain. \nA. Vitello intestinal duct, B. Urachus, C. Oganic diaphragm, D. None", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]