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 emeiocytosis or reverse pinocytosis requires which ion 
Select and explain. 
A. Na+, B. K+, C. Ca++, D. Mg++
C: Ca++
Answer: C: Ca++ 
Explanation: C i.e. Ca++