In terms of political power, african americans in the south during reconstruction
a. made great gains by winning political office throughout the north.
b. decided not to participate in government because they felt it wouldn't make a difference.
c. weren't allowed to vote and didn't do well politically.
d. made great gains by winning political office throughout the south.

The quote below is an excerpt from the charter of the united nations: "the purposes of the united nations are: to maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace . " source:this section implies that the united nations is prepared to do what to keep world peace?