Biology

The correct answer is B.The diversity and stability of an ecosystem.

Keystone species are organisms that have a disproportionately large effect on the structure and functioning of their ecosystem relative to their abundance or biomass. Their role helps to maintain the diversity and stability of the ecosystem by influencing the populations of other species, often in ways that promote a balanced and healthy ecosystem.

Why the other options are not correct:

A.The number of predators: While keystone species can include predators, their role isn't specifically to regulate the number of predators but to maintain the overall balance of the ecosystem.

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