This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'A 10oC decrease in temperature causes decrease in cerebral metabolic rate by \nSelect and explain. \nA. 10%, B. 30%, C. 50%, D. 70%', 'role': 'user'}, {'content': 'Answer: D \nExplanation: With each degree fall in temperature the metabolic rate is reduced by 7%, so by reducing temperature by 10degC the metabolic rate can be reduced by 70% and cerebral coex can be protected for 10 minutes at 30degC and for 1 hour at 15degC.', 'role': 'assistant'}]