You are answering a USMLE-style medical question. Question: A 4-year-old boy presents for a routine checkup. The patient’s parents say he was doing well until a few weeks ago at which time he started to complain of daily abdominal cramps and occasional muscle pains. His mother also noticed that he has been less active than usual. The parents deny any complaints of headaches or convulsions. The family lives together in a house built in 1950. The patient’s temperature is 36.8°C (98.2°F), blood pressure is 100/70 mm Hg, pulse is 100/min and respirations are 20/min. Abdominal exam shows mild diffuse tenderness to palpation and normal bowel sounds. The patient’s height, weight, and head circumference are normal. Laboratory results are as follows: Hemoglobin 7 g/dL Mean corpuscular volume (MCV) 72 Lead level (capillary blood) 15 mcg/dL Lead level (venous blood) 60 mcg/dL Findings on a peripheral blood smear are shown in the image. Which of the following is the best treatment option for this patient? Options: A) Trientine B) Calcium disodium edetate (EDTA) C) Penicillamine D) Dimercaptosuccinic acid (DMSA), also known as succimer Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.