It was the Northwest Ordinance that provided a plan for gorverning western territories, since it was thought that this would help the United States expand in a peaceful and organized manner.
B - during the Mauryan Empire
Asoka was the last major emperor of the Mauryan Dynasty. He reigned between 265-238 BCE and died in 238 BCE.
Slavery started because people couldn't do their jobs themselves, so they had other people do it for them.
I may be wrong but I'm pretty sure it's B, because the Vietnam War reunified Vietnam into a single communist country, so C and D are out, and Cambodia was involved in the war, so that takes A out too, so only B remains.
