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
Active transpo across the cell membrane is mediated by : 
Select and explain. 
A. G-proteins, B. Na+-K+ ATPase, C. Carrier protein, D. Channel protein
C: Carrier protein
Answer: C: Carrier protein 
Explanation: C i.e. Carrier protein