Elephants Are Not the Most Dominant Species in African Grasslands,yet

Elephants are not the most dominant species in African grasslands,yet they influence community structure.The grasslands contain scattered woody plants,but they are kept in check by the uprooting activities of the elephants.If the elephants are taken away,the grasslands convert to forests or to shrublands.The newly growing forests support fewer species than the previous grasslands.Which of the following describes why elephants are the keystone species in this scenario?

A) Elephants have a disparate influence on communities relative to their abundance.
B) Grazing animals depend upon the work of elephants to convert forests to grassland.
C) Elephants prevent droughts in African grasslands by uprooting shrubs and trees.
D) Elephants are the largest of all the herbivorous mammals in their communities.
E) Elephants help other populations survive by keeping out many large predators.