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: Medicine
[{'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: m/c cause of ACTH dependent cushings syndrome is PITUTATRY ADENOMA. M/C cause of ACTH independent cushings syndrome is IATROGENIC STEROIDS. OVER ALL M/C cause of cushings syndrome is IATROGENIC STEROIDS. Reference : page 2314 Harrison&;s Principles of Internal Medicine 19th edition', 'role': 'assistant'}]