This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proptosis, Enophthalmos, Developmental Anomalies, Subject name: Ophthalmology
[{'content': 'Intermittent proptosis is seen in? \nSelect and explain. \nA. Orbital tumor, B. Orbital cellulitis, C. Orbital varices, D. Cavernous sinus thrombosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: ANSWER: (C) Orbital varicesREF: Khurana 4th ed p. 381Causes of intermittent proptosis:Orbital varicesPeriodic orbital edemaRecurrent orbital hemmorrhageHighly vascular tumor', 'role': 'assistant'}]