A 5-year-old child ingests 50 iron tablets, each with 27 mg of iron. Within 6 hours the child develops abdominal pain and lethargy. On physical examination he is hypotensive. Laboratory studies show metabolic acidosis. Through formation of which of the following compounds is the cell injury in this child most likely mediated?
A) Ascorbic acid
B) Hemosiderin
C) Hydroxyl radical
D) Nitric oxide
E) Superoxide dismutase