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: ENT
The main vessel involved in bleeding from Juvenile nasopharyngeal angiofibroma: 
Select and explain. 
A. Facial aery, B. Ascending pharyngeal aery, C. Internal maxillary aery, D. Anterior ethmoidal aery
C: Internal maxillary aery
Answer: C: Internal maxillary aery 
Explanation: Ans: C. Internal maxillary aery(Ref Dhingra 7/e p281-282, 5/261-263)Juvenile Nasopharyngeal Angiofibroma:MC benign tumor of nasopharynx (but overall angiofibroma rare).MC site:Posterior pa of nasal cavity close to the margin of sphenopalatine foramen.Seen exclusively in males of 10-20 years.Testosterone dependent tumor - Seen in pre-pubeal to adolescent males.Features:Locally invasive vasoformative tumor consisting of endothelium lined vessels with no muscle coat.Main feeding vessel in most cases = Internal maxillary aery.Internal maxillary aery - External carotid aery branch.