For the first one The institution of slavery contradicted the foundation of the American society because till this day people of color are still being treated horrendously due to their ancestors and their teachings to the newer generation. Also it contradicted it because Americans had their amendments but it didn’t apply to slaves .
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.
Hernan cortes was aided by Spain to get gold and silver from the Aztecs or just to explore then he found the Aztec empire. He wasn't aided very well in troops, so sense they carried small pox the Aztecs got infected which killed a big majority of them while the conquistadors also attacked. <span />
A. It brought them domestic animals they had never seen before.
The answer would be (C) because it is the only secondary source of these choices.