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
An increase in external K+  concentration: 
Select and explain. 
A. Decrease RMP, B. Increase RMP by  –10 mv for each 10 mEq/L increase in K+, C. No change, D. Increase RMP by –20 mv for each 10 meq/L increase in K+
A: Decrease RMP
Answer: A: Decrease RMP 
Explanation: With hyperkalemia, membrane voltage is depolarized gradually. Depolarization of membrane voltage means decrease in RMP. Remember, a decrease in the membrane potential (RMP) means that the voltage has moved closer to ground (0 mv) or become more positive.