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': 'A common electrolyte used for plating copper indirect dies is: \nSelect and explain. \nA. Copper cyanide, B. Ionic copper, C. Acidic copper sulfate, D. Silver cyanide', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]