This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Myocardial Infarction, Subject name: Pathology
In myocardial reperfusion injury, the maximum effect is caused due to which of the following? 
Select and explain. 
A. Neutrophil, B. Monocytes, C. Eosinophils, D. Free radicals
D: Free radicals
Answer: D: Free radicals 
Explanation: Restoration of blood flow to ischemic tissues can promote recovery of cells if they are reversibly injured. However, under ceain circumstances, when blood flow is restored to cells that have been ischemic but have not died, injury is paradoxically exacerbated and proceeds at an accelerated pace. This process is called ischemia-reperfusion injury. It is due to sudden influx of free radicals and Ca+2