Answer: I think the answer is C
Explanation: West Berlin shows it.
Spain spent much of the 1920s under the dictatorship of Miguel Primo de Rivera, and the economic hardships caused by the Great Depression intensified polarization within the Spanish public. Labor unrest was widespread in the early 1930s, and the election of February 16, 1936, brought to power a leftist Popular Front government. Fascist and extreme-right forces responded in July 1936 with an army mutiny and coup attempt that expanded into a civil war.
Schools in the United States started integrating in the 1950's as a direct result of the Brown v Board of Education Supreme Court ruling.