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
Largest cross-sectional area 
Select and explain. 
A. Aery, B. Veins, C. Capillaries, D. Venules
C: Capillaries
Answer: C: Capillaries 
Explanation: 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