This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrine, Subject name: Pathology
[{'content': 'Which is the least common thyroid malignancy? \nSelect and explain. \nA. Papillary carcinoma, B. Follicular carcinoma, C. Medullary carcinoma, D. Anaplastic carcinoma', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Anaplastic carcinoma * Least common type of thyroid carcinoma is anaplastic type.* Most common type of thyroid carcinoma is papillary carcinoma (75%-85%) followed by follicular carcinoma (10-15%), medullary carcinoma (5%) and anaplastic carcinoma (<5%).", 'role': 'assistant'}]