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: Pediatrics
[{'content': 'Most common type of congenital adrenal hyperplasis is \nSelect and explain. \nA. 11 β Hydroxylase deficiency, B. 21 Hydroxylase deficiency, C. 17 α Hydroxylase deficiency, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]