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: Unknown
[{'content': 'Keratitis is caused by \nSelect and explain. \nA. Bacteria, B. Atopy, C. Protozoa, D. All', 'role': 'user'}, {'content': "Answer: D \nExplanation: Causes of keratitis\n\xa0\nInfective keratitis\nBacterial\nViral\nFungal\nChlamydial\nProtozoal\nSpirochactal\n\xa0\nAllergic keratitis\nPhlyctenular keratitis\nVernal keratitis\nAtopic keratitis\n\xa0\nTrophic keratitis\nExposure keratitis\nNeuroparalytic keratitis\nKeratomalacia\nAtheromatous ulcer\n\xa0\nKeratitis associated with diseases of skin and mucous membrane.\nKeratitis associated with systemic collagen vascular disorders.\nTraumatic keratitis, which may be due to mechanical trauma, chemical trauma, thermal burns, radiations.\n\xa0\nIdiopathic keratitis e.g.,\n\nMooren's corneal ulcer\nSuperior limbic keratoconjunctivitis\nSuperficial punctate keratitis of Thygeson", 'role': 'assistant'}]