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: Surgery
[{'content': 'Metabolic changes in burns include all except \nSelect and explain. \nA. Metabolic acidosis, B. Positive nitrogen balance, C. Hypermetabolic rate, D. Electrolyte imbalance', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Burns is characterized by negative nitrogen balance.', 'role': 'assistant'}]