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: Gynaecology & Obstetrics
[{'content': 'Barr body is present in all except \nSelect and explain. \nA. Klinefelter syndrome, B. Turner syndrome, C. Mullerian agenesis, D. Congenital adrenal hyperplasia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Karyotype of Turner syndrome = 45X0.\nNo barr body, as there is no extra X chromosome.', 'role': 'assistant'}]