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': 'Which of the following gene defects is associated with development of medullary carcinoma of thyroid - \nSelect and explain. \nA. Ret proto oncogene, B. FAP gene, C. Rb gene, D. BRCA 1 gene', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]