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
Distribution of blood flow is mainly regulated by the: 
Select and explain. 
A. Arteries, B. Arterioles, C. Capillaries, D. Venules
B: Arterioles
Answer: B: Arterioles 
Explanation: None