Gravity. Gravity was a theory crafted by man
Trench warfare was the main style of war during World War I. It consisted of both sides of the war, called fronts, digging trenches in the ground for their soldiers to live and fight in. Trenches were deep ditches dug in the ground that were often cramped and dirty. As the dug trenches further forward, they would take more land in the battle.
This was a very slow process and often would result in tens of thousands of casualties for a few yards of land. This is especially true because of the heavy use of mounted machine guns that both sides of the war used. These guns would tear through enemies easily. This style of warfare was also vulnerable to bombings and gas attacks, as the soldiers were stuck in the trenches and the heavy poisonous gasses would sink into the trenches.
The answer would be that the U.S. gained territory that needs to be admitted into the country as either free or slave states. Hope this helps you!
From my understanding of the Rwandan genocide, the Tutsis once held power in Rwanda for many years leaving Hutus as the minority. So I would have to say the answer is A