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': 'A young 25 year old man following A presented with proptosis (pulsatile in nature) ,chemosis and pain in right eye after 4 days. On Examination there was bruit on forehead and right eye. The probable diagnosis is \nSelect and explain. \nA. Cavernous sinus thrombosis, B. Carotico cavernous Fistula, C. Fracture sphenoid, D. Internal Carotid Aery Aneurysm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Carotico cavernos Fistula', 'role': 'assistant'}]