This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epistaxis, Subject name: ENT
Which artery is responsible for epistaxis after ligating of external carotid artery? 
Select and explain. 
A. Ethmoidal artery, B. Greater palatine artery, C. Superior labial artery, D. Ascending pharyngeal
A: Ethmoidal artery
Answer: A: Ethmoidal artery 
Explanation: Answer: (A) Ethmoidal arteryREF: Dhingra 4th ed p. 140Both anterior and posterior ethmoidal arteries are branches from internal carotid artery not external carotid artery