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: Anaesthesia
Which of the following makes the nerve membrane more susceptible to action of local anaesthetic 
Select and explain. 
A. Increased extracellular potassium, B. Increased extracellular calcium, C. Increased extracellular sodium, D. Decreased extracellular chloride
A: Increased extracellular potassium
Answer: A: Increased extracellular potassium 
Explanation: Increased extracellular K+ implies nerve is actively firing, thus more susceptible to anaesthetic agents.