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': 'Which of the following is a variant of papillary thyroid carcinoma? \nSelect and explain. \nA. Columnar cell, B. Insular, C. Huhle cell carcinoma, D. Medullary', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Variants of papillary carcinoma thyroid : Pure papillary Follicular variant Diffuse sclerosing variant Tall cell, Columnar cell variant Insular and huhle cell carcinoma are variant of follicular carcinoma of thyroid. Medullary cell carcinoma is carcinoma arising from C cell. Ref: Harrison 17/e, Page 2242.', 'role': 'assistant'}]