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': 'For which one of the following tumours Gastrin is a biochemical marker: \nSelect and explain. \nA. Medullary carcinoma of thyroid, B. Pancreatic neuroendocrine tumour, C. Pheochromocytoma, D. Gastrointestinal stromal tumor', 'role': 'user'}, {'content': 'Answer: B \nExplanation: . Pancreatic neuroendocrine tumour', 'role': 'assistant'}]