Final answer:
African Americans in the post-Civil War era responded to the hostile environment in the South by migrating North, engaging in peaceful protests and advocacy for civil rights, and forming armed self-defense groups.
Step-by-step explanation:
In the post-Civil War era, African Americans in the South responded to the hostile environment in several ways. They migrated to the North in search of better opportunities, engaged in peaceful protests and advocacy for civil rights, and some formed armed self-defense groups to protect their communities.
This response is represented by option d. All of the above.
One example of African Americans migrating to the North is the Great Migration, which brought many to northern cities in search of new opportunities. They faced discrimination and violence in the South and hoped to escape these challenges in the North. Peaceful protests and advocacy for civil rights were also common methods of resistance. African Americans used legal challenges and grassroots activism to begin dismantling racial segregation. Lastly, some formed armed self-defense groups, such as the Deacons for Defense and Justice, to protect their communities in the face of violent opposition.