How did westward expansion affect Native American tribes? a
Railroad expansion allowed Native American hunters to sell bison meat and hides at higher rates than before.

b
Railroad expansion brought U. S. settlers in contact with bison, drastically reducing the population of this food source.

c
Westward migration of U. S. settlers increased the number of farms, causing a supplementation of bison meat with grains.

d
Westward migration of slave-owning settlers diminished the demand for bison as a beast of burden, causing the bison population to increase.

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?