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: Medicine
[{'content': "True about Gardner's syndrome is except \nSelect and explain. \nA. CNS tumor, B. Osteoma, C. Dermoid tumour, D. Colonic polups", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]