According to paragraph 5, what indicates that grazing is more essential in grasslands than in other ecological communities? A. The animals that graze on grasslands include more natural herbivores than livestock, which is usually not true of other ecological communities. B. Adaptation to the disturbance of grazing causes grassland plants to grow more slowly than plants in other ecological communities. C. In grasslands herbivores consume a higher percentage of the plant material than they do in other ecological communities. D. Grazing is a harmful disturbance in grasslands but not in other ecological communities.