This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid Malignancies, Subject name: Surgery
[{'content': 'Patient treated previously by irradiation to neckdevelops a single solitary nodule- \nSelect and explain. \nA. Papillary ca thyroid, B. Follicular CA thyroid, C. Medullary CA, D. Hurthle cell CA', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Papillary CA thyroid", 'role': 'assistant'}]