This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
[{'content': 'Night blindness is due to: \nSelect and explain. \nA. Vitamin A deficiency, B. Retinitis pigmentosa, C. High myopia, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: d all of the above refkhurana 3 rd/e p. 289', 'role': 'assistant'}]