This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Water, Subject name: Social & Preventive Medicine
[{'content': 'Which of the following is used as an indicator for recent fecal contamination of water? \nSelect and explain. \nA. E coli, B. Cornybacterium diptheriae, C. Pseudomonas, D. Streptococci', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ANSWER: (D) StreptococciREF: Park 20th edition page 630BIOLOGICAL INDICATORS OF FECAL CONTAMINATION OF WATER:Coliforms: E.coli (fecal group), Klebsiella aerogens (non fecal group)Fecal streptococci - they indicate recent contamination of waterCLperferingens - they resist chlorination in doses normally used.Note: No E. coli or thermotolerant bacteria should be identified in any 100 ml of sample of water intended for drinking, or treated water entering distribution system.', 'role': 'assistant'}]