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 incidence of lymph node metastasis in carcinoma cervix stage II is : \nSelect and explain. \nA. 5-10 %, B. 15-20 %, C. 25-40 %, D. 50-60', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 15-20 %', 'role': 'assistant'}]