The THREE reasons that Radical Republicans turned to military Reconstruction after the Civil War are:
B. to punish Southern states for their role in the conflict
D. to protect the rights of newly freed slaves in the South
E. to speed up the process of readmitting states to the Union
These options reflect the Radical Republicans' goals of ensuring civil rights for freed slaves, holding Southern states accountable for their actions during the war, and working to facilitate their reintegration into the Union under more stringent conditions.