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
Abbe-Estlander Flap is based on: 
Select and explain. 
A. Facial artery, B. Labial artery, C. Maxillary artery, D. Ascending pharyngeal artery
B: Labial artery
Answer: B: Labial artery 
Explanation: Abbe-Estlander / Lip switch flap is used in post-operative lip reconstruction in cases of carcinoma lip which is based on labial artery.