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: Medicine
[{'content': 'The regional arterial resistance of the mesentery and kidney vessels is reduced by - \nSelect and explain. \nA. Dopamine, B. Dobutamine, C. Nor adrenaline, D. Isoprenaline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]