This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
A 6-year-old boy is admitted to the ward with drowsiness, dull deep tendon reflexes and seizures. On examination the child has a line on gums and there is a history of constipation. Which will be most appropriate drug that should be used for this child? 
Select and explain. 
A. EDTA, B. DMSA, C. BAL, D. Pencillamine
A: EDTA
Answer: A: EDTA 
Explanation: A child with drowsiness, decreased deep tendon reflexes, seizures and grey line on gums suggests a diagnosis of Lead Poisoning, which can be treated with chelating agents like EDTA. Ref: Harrison's Principles of Internal Medicine - 16th Edition, Page 2404; Ghai Essential Pediatrics - 6th Edition, Page 133; KD Tripathy Pharmacology 5th Edition, Page 812-815; Nelson 17th Edition, Page 2360,2361.