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: Dental
[{'content': 'Nephrotoxicity of fluoride is: \nSelect and explain. \nA. 400-500 μg/dl, B. 800-900 μg/dl, C. 850-950 μg/dl, D. 1000-1200 μg/dl', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]