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': 'The lethal dose of fluoride for 70 kg adult is: \nSelect and explain. \nA. 32-64 mg of fluoride/kg body weight, B. 50-60 mg of fluoride/kg body weight, C. 30-70 mg of fluoride/kg body weight, D. 60-80 mg of fluoride/kg body weight', 'role': 'user'}, {'content': 'Answer: A \nExplanation: CERTAINLY LETHAL DOSE (CLD) :\xa032 -\xa064 mg of fluoride/kg body wt.\nSAFELY TOLERATED DOSE (STD) :\xa08 - 16 mg of fluoride/kg body wt.\nRef: Soben peter 5th edition pg no:280', 'role': 'assistant'}]