Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called
- AKeystone speciesCorrect
- BAllopatric species
- CSympatric species
- DThreatened species
Explanation
Keystone species are organisms that play a critical role in maintaining the structure of an ecological community. They exert a disproportionately large influence on their environment relative to their abundance. Their presence or absence significantly impacts the survival and persistence of many other species within the same habitat.
For clarity, here is why the other options are incorrect:
Allopatric species refers to species that occupy different geographical areas and are separated by physical barriers.
Sympatric species refers to species that evolve into separate species while inhabiting the same geographic area.
Threatened species refers to any species which is likely to become endangered within the foreseeable future.

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