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: Ophthalmology
[{'content': 'Paralysisof 3rd, 4th, 6th nerves with involvement of ophthalmicdivisionof5thnerve, localizes the lesion to \nSelect and explain. \nA. Apex of orbit, B. Brainstem, C. Cavernous sinus, D. Base of skull', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ipsilateral ophthalmoplegia \xa0causing diplopia occur due to 3rd, 4th \xa0& 6th cranial nerves.\n6th nerve passes through cavernous sinus and others are related to the lateral wall of cavernous sinuses.', 'role': 'assistant'}]