According to Frederick Jackson Turner,what Crisis Did the United States

Multiple Choice

According to Frederick Jackson Turner,what crisis did the United States face at the end of the nineteenth century?

A) Increased likelihood of wars with Europe
B) Greater concern about the constitution and constitutional change in twentieth-century America
C) Greater concern about the impact of the "closing" of the western frontier
D) Increased racial and ethnic problems arising from Amerindians, blacks, and immigrants
E) Heightened international tensions about America´s growing military power