This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'Problem village if water is in depth more than \nSelect and explain. \nA. 5 mts, B. 10 mts, C. 15 mts, D. 20 mts', 'role': 'user'}, {'content': 'Answer: C \nExplanation: A "problem Village" has been defined as one where :No source of safe water is available within a distance of 1.6 km ORWater source has excess salinity, iron, fluorides & other toxic elements ORWater is exposed to the risk of choleraWater is available at a depth of more than 15 mts OR', 'role': 'assistant'}]