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
Structures passing through middle pa of superior orbital fissure 
Select and explain. 
A. Trochlear nerve, B. Nasociliary nerve, C. Lacrimal nerve, D. Trigeminal nerve
B: Nasociliary nerve
Answer: B: Nasociliary nerve 
Explanation: superior orbital Lateral pa: Lacrimal and frontal nerves, trochlear nerve, superior ophthalmic vein, meningeal branch of lacrimal aery, anastomotic branch of middle meningeal aery which anastomoses with recurrent branch of lacrimal aery middle pa Upper and lower divisions of oculomotor nerve, nasociliary nerve, abducent nerve Medial pa Inferior ophthalmic vein; sympathetic nerve from plexus around internal carotid aery Ref BDC volume 3;Sixth edition pg 56