Which of the following describes how biodiversity contributes to the sustainability of a natural environment?

a.
non-native kudzu out-compete native plants in the eastern united states.

b.
ground termites from china compete with native termites in the southeastern united states.

c.
acacia trees of central and south america provide food for stinging ants, while the stinging ants sting other insects on the trees.

d.
european common pine shoot beetles feed on the shoots of pine trees in the northeastern united states, causing a decrease in the trees' heights and growth.