This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
Dilator papillae are supplied by 
Select and explain. 
A. Oculomotor nerve, B. Sympathetic fibers from the fronto - orbital branch of trigeminal nerve, C. Postganglionic sympathetic fibers from cervical sympathetic chain, D. Postganglionic parasympathetic fibers
C: Postganglionic sympathetic fibers from cervical sympathetic chain
Answer: C: Postganglionic sympathetic fibers from cervical sympathetic chain 
Explanation: Dilator papillae are supplied by sympathetic fibers, which arises from the inter medio lateral horn of spinal cord segment of T-1 These pre-ganglionic T-1 sympathetic fibersclimbs up the cervical sympathetic chain and synapse in the superior (highest)cervical ganglion. Postganglionic fibers makes sympathetic plexus around the internal carotid aery and reach the dilator papillae muscle. Ref: Gray's 39e/p-227