The information in paragraph 12 helps to refine which of the author's claims?
A.
The beauty of the United States' mountains match that of any foreign mountain range.
B.
The United States' natural treasures are in many ways superior to those of other nations.
C.
The establishment of the national park system has allowed Americans many new opportunities.
D.
There are a number of geographic features in the United States that cannot be found anywhere else.