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: Biochemistry
[{'content': 'which one is the trace element? \nSelect and explain. \nA. Copper, B. sodium, C. calcium, D. Fats', 'role': 'user'}, {'content': 'Answer: A \nExplanation: i) Microminerals (Trace elements)- less than 100mg/day a) Copper b) Iodine c) Iron d) Mangnese e) Selenium f) Zinc', 'role': 'assistant'}]