This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment, Subject name: Social & Preventive Medicine
Potable water is defined as :- 
Select and explain. 
A. Zero coliforms per 100 ml, B. One coliform per 100 ml, C. 10 coliforms per 100 ml, D. 100 coliforms per 100 ml
A: Zero coliforms per 100 ml
Answer: A: Zero coliforms per 100 ml 
Explanation: - Drinking water, also known as potable water, is water that is safe to drink or to use for food preparation. - 'Potable water' is defined as: zero coliforms in any amount of drinking water. - Bacteriological indicators of water quality in India: Coliforms -Overall best indicator. Fecal streptococci - Indicate recent contamination of drinking water. Clostridium perfirenges - Indicate remote contamination of drinking water.