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: Surgery
[{'content': 'Abbe-Estlander Flap is based on: \nSelect and explain. \nA. Facial artery, B. Labial artery, C. Maxillary artery, D. Ascending pharyngeal artery', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Abbe-Estlander / Lip switch flap is used in post-operative lip reconstruction in cases of carcinoma lip which is based on labial artery.', 'role': 'assistant'}]