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
All of the following canals open on the posterior
wall of the pterygo palatine fossa EXCEPT 
Select and explain. 
A. Greater palatine canal, B. Foramen Rotundum, C. Pterygoid canal, D. Palatovaginal canal
A: Greater palatine canal
Answer: A: Greater palatine canal 
Explanation: Pterygopalatine Fossa:

This is a small pyramidal space situated deeply, below the apex of orbit.

Communications:

Anteriorly : With orbit through inferior orbital fissure.
Posteriorly :
	
With middle cranial fossa through foramen rotundum.
With foramen lacerum through pterygoid canal.
With pharynx through palatinovaginal canal.


Medially : With nose through sphenopalatine foramen.
Laterally : With infratemporal fossa through pterygomaxillary fissure.
Inferiorly : With oral cavity through greater & lesser palatine canals.