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: Medicine
[{'content': 'Pseudohermaphroditism in a female child is most commonly due to - \nSelect and explain. \nA. 21 α hydroxylase deficiency, B. 17 α hydroxylase deficiency, C. 11 β hydroxylase deficiency, D. 3 β Hydroxysteroid dehydrogenase deficiency', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Classic 21 α hydroxylase deficiency is the most common cause of Ambiguous genitalia in a new born.\n\nPseudo hermaphroditism\n\nA congenital abnormality of the external genitalia and of the body in which one possesses sex glands of one sex but genitals of the opposite sex.', 'role': 'assistant'}]