In the savanna ecosystems, the most dominant plant-eating animals are primarily the zebra and antelope. These animals have adapted superbly to the grasslands, thriving on the abundant grasses found in their habitats. While other animals listed, such as giraffes and buffalo, do inhabit savannas, zebras and antelope represent the most numerous herbivores found within these landscapes.
Zebras play an essential role in maintaining the health of the grasslands. They graze on grass, which helps to control its height and density, promoting new growth. Antelope, on the other hand, not only feed on grass but also consume shrubs and other plants, thus contributing to the ecological balance.
In contrast, horses are not native to most savanna regions, kangaroos are primarily associated with Australian habitats, and insects, while abundant, do not dominate the biomass compared to larger herbivores. Cattle are found in some savanna areas due to human agriculture but do not qualify as a dominant species in the wild.
In conclusion, the correct options for dominant plant-eating animals in the savanna would be b) zebra and g) antelope.