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: Medicine
[{'content': "Which of the following is true of Wilson's disease \nSelect and explain. \nA. increased urinary excretion of copper, B. increased ceruloplasmin in blood, C. decreased copper and ceruloplasmin in serum, D. decreased urinary excretion of ceruloplasmin", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]