This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Physiology
For sodium - Potassium pump the coupling ratio is 
Select and explain. 
A. 1:01, B. 2:03, C. 3:02, D. 1:04
C: 3:02
Answer: C: 3:02 
Explanation: Ans. (c) 3:2Na K pump uses the energy to move 3 sodium ions from inside to outside of the cell and moves 2 potassium ions from outside to insideThe coupling ratio is 3:2