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 bodies are not present in : \nSelect and explain. \nA. XO, B. XXY, C. XX, D. XXX', 'role': 'user'}, {'content': 'Answer: A \nExplanation: XO', 'role': 'assistant'}]