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': 'Vit A deficiency produces -a) Bitots Spotsb) Trantas spotsc) Keratomalaciad) Xerophthalmia e) Color blindness \nSelect and explain. \nA. abc, B. ad, C. bc, D. acd', 'role': 'user'}, {'content': "Answer: D \nExplanation: The most characteristic and specific signs of vitamin A deficiency are eye lesions.\nThese develop before the age of 2 years.\nThe term xerophthalmia comprises all the occular manifestations of vitamin A deficiency.\n\nXerophthalmia (Dry eye) \n\nIt is a syndrome due to deficiency of vitamin A.\n\ta It has following stages\nNight blindness → Earliest ocular symptom\nConjunctival xerosis →\xa0Earliest ocular sign\nBitot's spot\nCorneal xerosis\nKeratomalacia & corneal ulcers", 'role': 'assistant'}]