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: Pathology
[{'content': 'Calcitonin is a marker of which of the following? \nSelect and explain. \nA. Pancreatic cancer, B. Lobular carcinoma of breast, C. Melanoma, D. Carcinoma of thyroid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Calcitonin level is elevated in medullary carcinoma of thyroid.', 'role': 'assistant'}]