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': 'Medullary carcinoma thyroid arises from - \nSelect and explain. \nA. Parafollicular cells, B. Cells lining the acini, C. Capsule of thyroid, D. Stroma of the gland', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]