This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Maternal and child care, Subject name: Social & Preventive Medicine
[{'content': 'Trace element is ------- % of body weight \nSelect and explain. \nA. 0.001, B. 0.01, C. 0.1, D. 1', 'role': 'user'}, {'content': 'Answer: B \nExplanation: TRACE ELEMENTS: These are elements required by the body in quantities of less than a few milligrams per day, It constitutes 0.01% of total body weight. e.g. iron, iodine, fluorine, zinc, copper cobalt, chromium, manganese, molybdenum, selenium, nickel, tin, silicon and vanadium. Ref: Park 25th edition Pgno : 660', 'role': 'assistant'}]