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': 'Vulva! carcinoma metastasizes to which lymph group : \nSelect and explain. \nA. Para aoic nodes, B. Superficial inguinal nodes, C. Internal iliac nodes, D. External iliac nodes', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Superficial inguinal nodes', 'role': 'assistant'}]