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: Physiology
[{'content': 'Perfusion pressure is \nSelect and explain. \nA. Arterial pressure, B. Venous pressure, C. Arterial–venous pressure difference, D. Pressure in left ventricle', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Perfusion pressure is arterial pressure minus venous pressure.', 'role': 'assistant'}]