This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
Paralysisof 3rd, 4th, 6th nerves with involvement of ophthalmic division of 5th nerve, localizes the lesion to- 
Select and explain. 
A. Cavernous sinus, B. Apex of orbit, C. Brainstem, D. Base of skull
A: Cavernous sinus
Answer: A: Cavernous sinus 
Explanation: Ipsilateral ophthalmoplegia causing diplopia occur due to 3rd, 4th & 6th cranial nerves. 6th nerve passes through cavernous sinus and others are related to the lateral wall of cavernous sinuses. Ref :ak khurana 6th edition pg no 410 REF IMG