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: Pediatrics
[{'content': 'Vitamin A deficiency is characterized by – \nSelect and explain. \nA. Bitot spot, B. Xerophthalmia, C. Night blindness, D. All of these', '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 eve) \n\nIt is a syndrome due to deficiency of vitamin A.\nIt has following stages\n\n\nNight blindness\xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0-->\xa0 Earliest ocular symptom\nConjuctival xerosis\xa0 \xa0 \xa0 \xa0 \xa0-->\xa0\xa0\xa0\xa0\xa0\xa0Earliest ocular sign\nBitot's spot\nCorneal xerosis\nKeratomalacia & corneal ulcers", 'role': 'assistant'}]