Biology

The correct answer is: B.A species that holds a habitat together.

A keystone species is one that has a disproportionately large effect on its ecosystem relative to its abundance or biomass. These species play a critical role in maintaining the structure, diversity, and functioning of the habitat. They can influence the population sizes of other species, the availability of resources, or the physical environment in ways that support a balanced ecosystem.

Keystone species are not necessarily the largest or most plentiful species in their habitat, nor do they have to always be ...