This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'Most undesirable mineral in water is \nSelect and explain. \nA. Iron, B. Copper, C. Zinc, D. Lead', 'role': 'user'}, {'content': "Answer: D \nExplanation: Iron in water leads to discolouration and failure of metal pipings. Zinc leads to an undesirable astringent taste and greasy film while boiling Copper stains laundry like Iron Chronic consumption of water with lead causes plumbism Park's Textbook of Preventive and Social Medicine, 25th edition, Page No. 780", 'role': 'assistant'}]