What is a keystone species?

Options

A. A common species that has plenty of biomass, yet has a fairly low impact on the community's organization.
B. A rare species that has minimal impact on the biomass and on other species in the community
C. A dominant species that constitutes a large proportion of the biomass and which affects many other species.
D. A species which makes up only a samll proportion of the total biomass of a community. Yet has a huge impact on the community's organization and survival.

Answer

D