This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pediatrics
[{'content': "The most common cause of Cushing's syndrome is: \nSelect and explain. \nA. Pituitary adenoma, B. Adrenal adenoma, C. Ectopic ACTH, D. Iatrogenic steroids", 'role': 'user'}, {'content': "Answer: D \nExplanation: d. Iatrogenic steroids(Ref: Nelson's 20/e p 2227-2729, Ghai 8/e p 525)The most common cause of Cushing's syndrome is prolonged exogenous administration of glucocorticoid hormones, especially at the high doses used to treat lymphoproliferative disorders.", 'role': 'assistant'}]