This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Circulation, Subject name: Physiology
[{'content': 'The percentage of blood that is present in capillaries is: \nSelect and explain. \nA. 5%, B. 10%, C. 15%, D. 20%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: At any given time: 54% of the total blood volume is contained within the venous compament; 10% in the aoa and aeries, 5% in the capillaries, 1% in the aerioles, 12% blood volume in the hea and 18% in the pulmonary circulation.', 'role': 'assistant'}]