This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid Gland, Subject name: Surgery
[{'content': 'Highly aggressive and lethal thyroid cancer: \nSelect and explain. \nA. Papillary, B. Follicular, C. Medullary, D. Anaplastic', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) Anaplastic CancerRef: Bailey and Love 27th Edition, Page 820* Lethal almost always in 6 months.* It can arise de novo or dedifferentiation of a papillary or poorly differentiated carcinoma** RT and CT does not increase survival', 'role': 'assistant'}]