This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2019, Subject name: Ophthalmology
[{'content': 'The most common cause of proptosis in adults:- \nSelect and explain. \nA. Orbital cellulitis, B. Preseptal cellulitis, C. Thyroid eye disease, D. Capillary hemangioma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Most common cause of unilateral proptosis in children is orbital cellulitis and in adults is thyroid ophthalmopathy. Most common cause of bilateral proptosis in children is neuroblastoma and leukemia (chloroma) and in adults is thyroid ophthalmopathy.', 'role': 'assistant'}]