This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nerve Physiology, Subject name: Physiology
All or none phenomenon is a feature of - 
Select and explain. 
A. Action potential, B. Local potential, C. Electronic potential, D. Post-synaptic potential
A: Action potential
Answer: A: Action potential 
Explanation: Ans. is 'a' i.e., Action potential