This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head & Neck, Subject name: Anatomy
Which cranial nerve carries parasympathetic fibers? 
Select and explain. 
A. Vagus nerve, B. Trigeminal nerve, C. Hypoglossal nerve, D. Abducent nerve
A: Vagus nerve
Answer: A: Vagus nerve 
Explanation: Ans. A. Vagus nerveThe only cranial nerves that transmit parasympathetic fibers are the oculomotor, facial, glossopharyngeal, and vagus nerves.Parasympathetic flow is cranio-sacral flow carried by cranial nerves: 3,7,9,10 and the sacral nerves: S-2,3,4. These nerves carry the preganglionic fibres to their respective ganglia.