[amp_mcq option1=”Less than 150″ option2=”Between 150 to 200″ option3=”Between 200 to 300″ option4=”More than 500″ correct=”option1″]
The correct answer is: A. Less than 150.
A dilution factor is a measure of how much water is mixed with sewage. The higher the dilution factor, the less sewage there is in the water. Sewage treatment is not necessary if the dilution factor is high enough, because the sewage will be diluted to the point where it is not harmful to the environment.
A dilution factor of less than 150 means that there is too much sewage in the water. This can cause problems such as pollution, disease, and even death. In these cases, sewage treatment is necessary to reduce the amount of sewage in the water and make it safe for the environment.
The other options are incorrect because they do not represent a dilution factor that is low enough to require sewage treatment. A dilution factor of between 150 and 200 is still high enough that sewage treatment is not necessary. A dilution factor of between 200 and 300 is even higher, and a dilution factor of more than 500 is very high. In all of these cases, sewage treatment is not necessary.