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': 'Indication for surgery in a case of adrenal incidentaloma - \nSelect and explain. \nA. Size > 5 cm, B. Bilateral adrenal metastasis, C. Functional tumor, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: According to CSDT nonfunctioning adrenal tumors larger than 5 cm in diameter should be removed because of the high risk of malignancy.', 'role': 'assistant'}]