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': 'Mature ovum contains: March 2013 \nSelect and explain. \nA. 23X, B. 46X, C. 45XO, D. 47XXY', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A i.e. 23X', 'role': 'assistant'}]