Which one of the following inferences about the biological characteristics of a temperate-zone grassland is most strongly supported by the passage? A. It has more different species than does a tropical-zone forest. B. Its climatic conditions have been severely interrupted in the past by succession of ice ages. C. If it has a large amount of biomass, it also has a large number of different species. D. It has a larger regional pool of species than does an arctic grassland. E. If population groups become isolated at its edges, they are likely to adapt to local conditions and become new species.