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
The electrogenic Na+ K+ ATPase plays a critical role in cellular physiology by 
Select and explain. 
A. Extruding 3 Na+ out of the cell in exchange for taking two K+ into the cell., B. Extruding 3 K+ out of the cell in exchange for taking two Na+ into the cell., C. Using the energy in moving Na+ into the cell or K+ outside the cell to make ATP., D. Using the energy in moving Na+ outside of the cell or K+ inside the cell to make ATP.
A: Extruding 3 Na+ out of the cell in exchange for taking two K+ into the cell.
Answer: A: Extruding 3 Na+ out of the cell in exchange for taking two K+ into the cell. 
Explanation: Na, K ATPase catalyzes the hydrolysis of ATP to adenosine diphosphate (ADP) and uses the energy to extrude three Na+ from the cell and take two K+ into the cell for each molecule of ATP hydrolyzed.