This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
All open into middle meatus except 
Select and explain. 
A. Frontal sinus, B. Sphenoid sinus, C. Maxillary sinus, D. Ethmoidal sinus
B: Sphenoid sinus
Answer: B: Sphenoid sinus 
Explanation: THE FOLLOWING FEATURES ARE: 1.Ethmoidal bulla 2.Hiatus semilunaris 3.Infundibulum 4.Opening of frontal air sinus 5.Opening of anterior ethmoidal sinus 6.Opening of maxillary sinus Ref BDC volume 3,sixth edition pg 243