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': 'Variant of papillary carcinoma thyroida) Medullaryb) Warthinc) Columnar celld) Insulare) Diffuse sclerosing \nSelect and explain. \nA. cde, B. bae, C. acd, D. cab', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]