This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
The maxillary sinus open intlo middle meatus at the level of: 
Select and explain. 
A. Hiatus semilunaris, B. Bulla ethmoidalis, C. Infundibulum, D. None of the above
A: Hiatus semilunaris
Answer: A: Hiatus semilunaris 
Explanation: Ref: Dhingra 7e pg 151,209.