Answer:B. imperialism
Explanation: becouse Imperialism- The domination by one country of the political, economic, or cultural life of another country or region.
(1) decline of the Ku Klux Klan<br />
(2) activities of the Freedmen’s Bureau<br />
(3) stationing of federal troops in the South<br />
(4) passage of Jim Crow laws
Answer: passage of Jim Crow Laws
Explanation: this happened during the times of Jim Crow and things only got worse.
Isolation created tension between North and South America.
B.
Isolation protected it during the World Wars.
C.
Isolation preserved Native American culture.
D.
Isolation kept sailors off the sea.