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': 'Nelson syndrome is associated with: \nSelect and explain. \nA. BRCA2 mutation, B. Prophylactic craniospinal irradiation, C. Subarachnoid hemorrhage, D. Bilateral adrenalectomy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Nelson syndrome refers to development of ACTH secreting pituitary macroadenoma after therapeutic bilateral adrenalectomy.', 'role': 'assistant'}]