This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
According to myogenic theory of renal autoregulation, the afferent aerioles contract in response to stretch induced by 
Select and explain. 
A. NO, B. Noradrenalin, C. Opening of Ca2+ channels, D. Adenosine release
C: Opening of Ca2+ channels
Answer: C: Opening of Ca2+ channels 
Explanation: Myogenic autoregulation - through opening of Calcium channels Tubuloglomerular feedback - through release of adenosine Ref: Ganong 25th ed/page 678