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': 'Binding of proteins to DNA is regulated by \nSelect and explain. \nA. Copper, B. Zinc, C. Selenium, D. Nickle', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]