Correct answer: E). All of the above
An ecosystem is said to be balanced when all the all the plants, animals and the non-living components of the environment are in harmony. It may get disturbed or loos its harmony when there is a increased pollution, an increase in the number of the human population etc.
Ecological balance occurs when nature or man caused the disturbance to the natural balance of the ecosystem. Ecological balance is very important in order to ensure that no particular organism or species is overused or exploited.
