Can someone summarize the reconstruction era for me? the period after the civil war

Reconstruction and led to the triumph of the more radical wing of the Republican Party. During Radical Reconstruction, which began in 1867, newly enfranchised blacks gained a voice in government for the first time in American history, winning election to southern state legislatures and even to the U.S. Congress. In less than a decade, however, reactionary forces–including the Ku Klux Klan–would reverse the changes wrought by Radical Reconstruction in a violent backlash that restored white supremacy in the South.

The answer is option b and c.