This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pathophysiology of Burn and Inhalation Injury, Subject name: Surgery
[{'content': 'In burns , back constitutes how much %- \nSelect and explain. \nA. 9%, B. 18%, C. 36%, D. 13.50%', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., 18%", 'role': 'assistant'}]