Which example best illustrates a way in which land is being used as a resource for the benefit of humans?

A. The Rocky Mountains are home to several endangered species of predatory birds.

B. The waters around Australia are home to the world’s largest coral reefs.

C. Scientists have now created an artificial fuel that will replace the use of coal as a fuel.

D. Land in a hilly valley is flattened to make building and road construction much easier.