After the southern Populist were defeated.
The South turned out to be completely isolated by law amid the 1890s, after the thrashing of the Populists and their endeavor to advance biracial, multiparty governmental issues. The Redeemers did not establish isolation or disfranchisement even after the Republicans in the North deserted southern blacks. After the War, the Reconstruction approaches of Republicans had made separation and isolation difficult until this day.
The Great Wall of China( built and maintained from the warring state period to the Ming dynasty)
The answer is (c) coastal plains
Focus on better democracy, and most importantly listen to the people’s voice because America is falling apart as people aren't listening to each other