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
[{'content': 'Most common cause of unilateral proptosis is- \nSelect and explain. \nA. Thyrotoxicosis, B. Retinoblastoma, C. Intraocular haemorrhage, D. Raised intracranial tension', 'role': 'user'}, {'content': 'Answer: A \nExplanation: *Thyroid orbitopathy is the most common cause of bilateral and unilateral proptosis. Ref: Head & Neck surgery 2nd/e p.1513', 'role': 'assistant'}]