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
According to myogenic hypothesis of renal autoregulation, the afferent aerioles contract in response to stretch induced by: 
Select and explain. 
A. No release, B. Narodrenaline release, C. Opening of Ca2+ channels, D. Adenosine release
C: Opening of Ca2+ channels
Answer: C: Opening of Ca2+ channels 
Explanation: C i.e. Opening of Ca2+ channels