The correct answer is B. An increase in the number of other grazing animals.
Explanation:
In ecosystems, one of the factors that can lead to the decrease of the population of an organism is competition, this occurs as organisms struggle to get the same resource such as food, water or shelter. Additionally, competition increases as more organisms need the same resource. This implies in the case of the impala that feeds on grass and plants if there is an increase in the number of other grazing animals, competition would increase and this would lead to a decrease in the population as some Impalas might not get enough food to survive.
