This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Circulation (Blood flow, Blood Pressure, Regional Circulation, Cardiovascular changes during exercise), Subject name: Physiology
[{'content': 'O2 consumption by the hea is determined primarily by \nSelect and explain. \nA. Intramyocardial Tension, B. Contractile state of hea, C. Hea rate, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: O2 consumption by the hea is determined primarily by the intramyocardial tension, the contractile state of the myocardium, and the hea rate. Ventricular work per beat correlates with O2 consumption', 'role': 'assistant'}]