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': "The appropriate choice for treatment of Nulliparous prolapse is : \nSelect and explain. \nA. Sling operation, B. Manchester repair, C. Ward Mayo's operation, D. Pessry treatment", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sling operation', 'role': 'assistant'}]