Answer:
E. climax
Explanation:
Even though it is not something that is very common in nature, there are still certain exceptions where certain communities manage to reach a point of equilibrium. This basically is a community of small number of dominant prominent species that create a stable ecosystem. This state of equilibrium is known as climax community. This type of community appears when the web of biotic interactions between the organisms becomes so intricate that there is no possibility of other species to be admitted in it.
I believe the correct answer is the third circle
Salinity refers to the principal characteristic that determines whether an aquatic ecosystem is classified as marine or freshwater. It is the measure of all the salts dissolved in water.