This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'RET proto-oncogene is associated with \nSelect and explain. \nA. MEN1, B. Medullary carcinoma of thyroid, C. Small cell carcinoma lung, D. Melanoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]