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': 'A water sample with hardness level of 1 meq/ L is classified as: \nSelect and explain. \nA. Soft water, B. Moderately hard water, C. Hard water, D. Very hard water', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Classification Hardness level (meq/L) Soft water < 1 Moderately hard water 1-3 Hard water 3-6 Very hard water >6 Ref: Park 21st edition page: 672.', 'role': 'assistant'}]