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': 'Snow blindness is caused due to \nSelect and explain. \nA. Extreme cold, B. UV  Rays, C. IR Rays, D. Vit A deficiency', 'role': 'user'}, {'content': "Answer: B \nExplanation: Snow blindness is a painful, temporary loss of vision due to overexposure to the sun's UV rays.", 'role': 'assistant'}]