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
Turbulence of blood flow increases when 
Select and explain. 
A. Viscosity, B. Diameter of blood vessel |, C. Density |, D. Straight aeries
B: Diameter of blood vessel |
Answer: B: Diameter of blood vessel | 
Explanation: According to Reynold&;s equation: Re= rDV/eWhere Re is the Reynolds number, named for the man who described the relationship; r is the density of the fluid; D is the diameter of the tube under consideration; V is the velocity of the flow, and e is the viscosity of the fluid.The higher the value of Re, the greater the probability of turbulenceTherefore increase in diameter cause increase in Re and hence increase turbulenceRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:540