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: Social & Preventive Medicine
[{'content': 'Confirmed case of fluorosis is defined by presence of fluoride in urine more than: \nSelect and explain. \nA. 1 mg/L, B. 3 mg/L, C. 5 mg/L, D. 7 mg/L', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Confirmed case of fluorosis is defined as presence of one or both of the following: High level of fluoride in urine >1mg/L Intraosseous membrane calcification in fore arm confirmed by Xray Ref: Health policies and programmes in India, D.K. Taneja 11th edition page: 329', 'role': 'assistant'}]