This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
[{'content': 'Largest cross-sectional area \nSelect and explain. \nA. Aery, B. Veins, C. Capillaries, D. Venules', 'role': 'user'}, {'content': "Answer: C \nExplanation: Capillaries have largest total c.s area which is 4500 cm2Ref: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:537 Table no:32-9", 'role': 'assistant'}]