The African savanna is a tropical grassland that supports grazing animals, such as antelopes and zebra. Predators, such as lions, hunt the grazing animals of the savanna. Small mammals, such as shrews and mice, burrow in soil beneath the grasses. Acacia trees often take root in the savanna. These trees are usually knocked down and eaten by elephants. Which of the following is likely to cause the greatest change in the vegetation of the savanna? A. an increase in the lion population
B. a decrease in the elephant population
C. an increase in the shrew population
D. a decrease in the antelope population