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
Which of the following increases turbulence in blood flow: 
Select and explain. 
A. When the diameter of the blood vessel increases., B. When density decreases., C. When resistance increases., D. All of the above.
A: When the diameter of the blood vessel increases.
Answer: A: When the diameter of the blood vessel increases. 
Explanation: Turbulence ∞ Re (Reynolds no) =ρDV/И 
So increase in density → increases Re → increases turbulence.