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 sodium-potassium pump is an example of 
Select and explain. 
A. Active transport, B. Passive transport, C. Facilitated diffusion, D. Osmosis
A: Active transport
Answer: A: Active transport 
Explanation: In Na+– K+ exchange, 3Na+ goes out and 2K+ goes into the cell with the utilization of ATP. 
Hence it is a primary active transport. Due to the net flow of Na+ outwards, there is a potential difference that occurs.