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': 'Trace element is what percent of body weight \nSelect and explain. \nA. 0.01%, B. 0.00%, C. 0.10%, D. 1%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]