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: Anatomy
What is maxillary air sinus? 
Select and explain. 
A. Paranasal air sinus situated close to maxilla, B. Venous sinus situated close to maxilla, C. Paranasal air sinus situated in maxilla, D. Venous sinus extending in to the maxilla
C: Paranasal air sinus situated in maxilla
Answer: C: Paranasal air sinus situated in maxilla 
Explanation: None