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': "During pomeroy's method of female sterilization, which poion of tube is ligated : \nSelect and explain. \nA. Isthmus, B. Ampullary, C. lsthmo-ampullary, D. Cornual", 'role': 'user'}, {'content': 'Answer: C \nExplanation: lsthmo-ampullary', 'role': 'assistant'}]