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
The following organism because of its easy culture methods is widely used as bacteriology indicator of water pollution – 
Select and explain. 
A. Foecal streptococci, B. Escherichia coli, C. Clostridium perfringens, D. Salmonella Typhi
B: Escherichia coli
Answer: B: Escherichia coli 
Explanation: None