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': 'Diagnostic tumor marker for medullary thyroid cancer : \nSelect and explain. \nA. BRAF, B. VMA, C. Calcitonin, D. Melatonin - 1', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Medullary carcinoma of thyroid arises from parafolicular or C - cell which secrete "calcitonin".', 'role': 'assistant'}]