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': "Ward Mayo's operation is indicated in : \nSelect and explain. \nA. Carcinoma uteus, B. Nullipara prolapse, C. Procidentia, D. Carcinoma cervix", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Procidentia', 'role': 'assistant'}]