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
Nelson syndrome is associated with: 
Select and explain. 
A. BRCA2 mutation, B. Prophylactic craniospinal irradiation, C. Subarachnoid hemorrhage, D. Bilateral adrenalectomy
D: Bilateral adrenalectomy
Answer: D: Bilateral adrenalectomy 
Explanation: Nelson syndrome refers to development of ACTH secreting pituitary macroadenoma after therapeutic bilateral adrenalectomy.