For question one the right answer is A. The agency’s power was weakened by conflict and political fighting. The Freedmen Organization was opposed by organizations in the South. Sometimes agents were harassed. Also president Andrew Johnson encouraged these organizations. This resulted in a total failure when trying to establish the free slaves as landowners.
For question two the right answer is C. 16. 16 African Americans served in the U.S. congress during reconstruction. And 600 more served in the States legislatures.
An oligarchy describes C. "rule by a small group". The size of this group can vary greatly but it relative to the size of the population its controlling and usually results and unfair governance.