How did Andrew Johnson's behavior in office influence the events of the Reconstruction era?

A) Johnson's behavior and use of the veto prevented Republicans from getting their bills passed without Southern Democrats supporting them.

B) Johnson's behavior fostered a more peaceful transition of power and rights between blacks and whites in the South.

C) Johnson's behavior cost him the presidency when he was successfully impeached, but ultimately acquitted, over his failure to adhere to Congressional legislation.

D) Johnson's behavior strengthened the unity between moderate and Radical Republicans, and prompted many Democrats to support them as well.