This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'In humans, end product of purine metabolism \nSelect and explain. \nA. Allantoin, B. Uric acid, C. CO2, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Question repeated', 'role': 'assistant'}]