This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mechanisms of Cell Injury, Subject name: Pathology
Fenton reaction leads to free radical generation when - 
Select and explain. 
A. Radiant energy is absorbed by water, B. H202 is formed by myeloperoxidase, C. Ferrous ion converted to ferric ion, D. Nitric oxide is converted to peroxynitrite
C: Ferrous ion converted to ferric ion
Answer: C: Ferrous ion converted to ferric ion 
Explanation: Ans. is 'c' i.e., Ferrous ions converted to ferric ions o Free radicals are generated through Fenton's reaction.o In this reaction iron is converted from its ferrous to ferric form and a free radical is generated,o The effect of these reactive species relevant to cells injury include;Lipid peroxidation of membranesOxidative modification of proteins and lesions in DMA.