Which is a major threat to biodiversity? A. Red-billed oxpeckers eat ticks off of impalas' coats in the grasslands of East Africa. B. Mining in the Guinean Forests of West Africa to provide diamond and gold jewelry for humans. C. Acacia trees of Central and South America provide food for stinging ants, while the stinging ants snip surrounding plants that grow too close. D. In Japan, hummingbird hawkmoths drink nectar from a species of flowering plants and transfer the plants' pollen to other flowering plants of the same species.