You are answering a USMLE-style medical question. Question: A 4-year-old child is rushed to the emergency department after developing sudden abdominal pain followed by nausea, vomiting, and dark, almost black-colored stool. Prior to the onset of symptoms, he was seen playing with his mother’s purse containing a bottle of vitamin supplements, which she takes for chronic microcytic anemia. Which of the following medications is the treatment for this patient's intoxication? Options: A) Dimercaprol B) Deferoxamine C) Protamine D) Succimer Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.