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
Antrochoanal polyp opens In which meant 
Select and explain. 
A. Middle meatus, B. Superior meatus, C. Inferior meatus, D. Sphenoethmoidal recess
A: Middle meatus
Answer: A: Middle meatus 
Explanation: ANTROCHOANAL POLYP most commonly seen in children.

They are unilateral, usually arises from the mucosa of maxillary antrum near its accessory ostium comes out of it & grows in the channel & nasal cavity.

Maxillary sinus opens into the middle meatus.