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': 'Level of Hardness if the value is 50-150 mg/L ? \nSelect and explain. \nA. Soft water, B. Moderately hard water, C. Hard water, D. Very hard water', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Moterately hard water", 'role': 'assistant'}]