Coliforms A. are an informal grouping of enterics. B. ferment lactose. C. includes E. coli. D. are used as indicators of fecal contamination. E. All of the choices are correct.

E. All of the choices are correct.

Explanation:

Coliforms bacteria belong to the family Enterobacteriaceae. These are the bacteria mostly present in the intestine of humans and other animals. These bacteria are an indicator of fecal contamination in water.

They lose their viability and exhibit the minimum growth in freshwater. The absence of these enteric bacteria in a specific volume of water is a criterion to consider the water as being potable.

Examples of coliform bacteria include E. coli, Enterobacter aerogenes, and Klebsiella pneumoniae. These are the facultative anaerobic bacteria and exhibit lactose fermentation for ATP production.