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
Sphenoidal air sinus is supplied by ___________ nerve: 
Select and explain. 
A. Posterior ethmoidal nerve, B. Posterior superior alveolar nerve, C. Sphenoidal nerve, D. Infratemporal nerve
A: Posterior ethmoidal nerve
Answer: A: Posterior ethmoidal nerve 
Explanation: None