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': 'Earliest feature of xerophthalmia is \nSelect and explain. \nA. Conjunctival xerosis, B. Bitot spots, C. Dry eye, D. Night blindness', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Earliest - Night blindness.', 'role': 'assistant'}]