According to the principle of competitive exclusion, two species cannot continue to occupy the same ) environmental habitatb) territoryc) ranged) ecological nichee) biome

C ecological niche

Explanation:

An ecological niche in a habitat, describe the interactions between a species, organisms with the other population of its community, in regards to distribution of resources, competition, predation and parasites.

According to the principle of competitive exclusion, two species can not continue to occupy exactly the same ecological niche in a habitat and coexist peacefully. Species with exactly the same niches will have similar needs and will compete for exactly the same limited resources such as food.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.