Answer:
New ways of governing were needed.
The people migrated to other lands.
The amount of trade dropped dramatically.
New schools were created to train scholars.
A "rational" use would mean a compromise between different interest and would also take into account scientific knowledge. Therefore neither a complete ban or unconditional permission on lumbering are rational.
A correct answer is
D. National forests should be protected to make the best use of the nation's natural resources.
The U.S gained many people of French heritage.
