Which of the following statements describes rational use of national forests? a. only large businesses should be allowed to harvest trees in national forests. b. there should be no restrictions on the land. c. national forests should be protected to make the best use of the nation's natural resources. d. national forests should ban lumbering completely.

There should be some limit on lumbering: without a limit it is likely that too much wood would be cut  and that the forest would  die.

On the other hand, a complete ban is too radical: in some cases some limited lumbering might make sense (even to help neighboring trees flourish).

The best answer is C.national forests should be protected to make the best use of the nation's natural resources.

The answer is option b and c.