What is a foundation species?

• A
  $A$ species that makes up a very small proportion of the total biomass of the community but has a large impact on community structure and biodiversity.
• B
  $A$ common species that has a large biomass but has very little impact on community structure.
• C
  $A$ rare species that has very little impact on biomass and other species in the community.
• D
  $A$ dominant species that makes up a large proportion of the biomass and influences many other species.