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: Pharmacology
[{'content': 'Dimercaperol is contraindicated in poisoning with- \nSelect and explain. \nA. Iron, B. Mercury, C. Gold, D. Silver', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is `a' i.e., Iron o Dimercaprol is contraindicated in iron and Cadmium Poisoning as Dimercaperol - Fe and Cd complexes are themselves toxic.", 'role': 'assistant'}]