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: Social & Preventive Medicine
[{'content': 'Hardness of water is contributed by following salts except- \nSelect and explain. \nA. Calcium gluconate, B. Magnesium chloride, C. Calcium sulfate, D. Magnisum bicarbonate', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Calcium gluconate o I lardness may be : - i) Temporary (Carbonate) hardness Calcium bicarbonate & Magnesium bicarbonate. It is called temporary because it can be removed by boiling or addition of lime. ii)Permanent (Non-Carbonate) hardness --> Calcium Sulfate, magnesium sulfate, Calcium chloride, magnesium chloride. It is called permanent because it cannot be removed by boiling.", 'role': 'assistant'}]