This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
[{'content': 'The vasodilatation produced by carbon dioxide is maximum in one of the following \nSelect and explain. \nA. Kidney, B. Brain, C. Liver, D. Hea', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The vasodilation produced by carbon dioxide is maximum in the brain Ref: guyton and hall textbook of medical physiology 12 edition page number:360,361,362', 'role': 'assistant'}]