Segregation was an useful tool in preserving the economic and social dominance of the white southerners. With segregation the African Americans were being discriminated against and kept in socially inferior position thus enabling the whites to get better paying jobs and generally better positions thus continuing the cycle of economical dominance of the white southerners.
If you mean World War II, the answer is Germany, it was divided by the Berlin Wall.
Channel Tunnel
or answer c is what you are looking for
They incorporated the Uyghur Turks
