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
According to the WHO, what is the minimum bacteriological standard for drinking water - 
Select and explain. 
A. All the samples should not contain coliform organisms, B. 3 consecutive samples of water should not contain any coil forms, C. 3 coliforms in a 100 ml water, D. I coliform in a 100 ml water
A: All the samples should not contain coliform organisms
Answer: A: All the samples should not contain coliform organisms 
Explanation: Ans. is 'a' i.e., All the samples should not contain coliform organisms