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': "In cervical incompetence, encirclage operation done are:a) Mc Donald operationb) Shirodkar operationc) Purandare's operationd) Khanna's sling operatione) Abdominal sling operation \nSelect and explain. \nA. ab, B. a, C. ad, D. bc", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]