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': "Unilateral proptosis with bilateral VI\nth\n nerve palsy,diagnosis is - \nSelect and explain. \nA. Grave's disease, B. Retinoblastoma, C. Pseudotumour of orbit, D. Cavernous sinus thrombosis", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Unilateral proptosis and bilateral 6th nerve polsy suggest the diagnosis of CST.\nBilateral 6th\xa0nerve palsy suggests the involvement of opposite side cavernous sinus. In more than 50% of the patients of CST opposite side is involved. 6th nerve is earliest to be involvement.', 'role': 'assistant'}]