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': 'Habrdness of water has a beneficial effect againts which one of the following - \nSelect and explain. \nA. Renal diseases, B. Metabolic diseases, C. Cerebrovascular diseases, D. Cardiovascular diseases', 'role': 'user'}, {'content': "Answer: D \nExplanation: Repos from several countries have shown an inverse statistical association between the hardness of drinking water and the death rate from cardiovascular diseases. Areas supplied with soft drinking water showed a significantly higher prevalence of either aeriosclerotic disease or degenerative hea disease, hypeension, the sudden death of cardiovascular origin. Park's Textbook of Preventive and Social Medicine, 25th edition, Page No. 787", 'role': 'assistant'}]