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
[{'content': 'Cranial nerve related to apex of petrous temoporal bone \nSelect and explain. \nA. VIII, B. VII, C. VI, D. IX', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cranial nerve 5 & 6 are related to apex of petrous bone.\nOnly 1st & 2nd cranial nerves do not arise from brain stem and so do not pass through posterior-cranial fossa. And all other C.N (i.e. 3rd to 12th) pass through posterior cranial fossa.\nTrochlear (4th) nerve is the only cranial nerve to emerge dorsally from the brain stem & has longest infra cranial course and most slender cranial nerve (in terms of axons it contains)', 'role': 'assistant'}]