This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cellular Pathology, Subject name: Pathology
In myocardium reperfusion injury is due to? 
Select and explain. 
A. Ca, B. Mg, C. K, D. Mn
A: Ca
Answer: A: Ca 
Explanation: Ans. (a) Ca(Ref: Gross GJ, Kersten JR, Warltier DC. Mechanisms of postischemic contractile dysfunction. Ann Thorac Surg. 1999; 68:1898-1904.)Mediators of reperfusion injury are: Oxygen Free Radicals, Endothelial Dysfunction and Microvascular Injury, Alterations in Calcium Handling