Since this is a timed test I'm pretty sure i'm too late to give the answer but it's C. Hope this helped (although i'm late)
Daesh was the group the claimed responsibility... But if you like conspiracy theories I think the government is trying to take our guns away so they stage these attacks to take over....
It actually lasted from 618 to 907.....907 - 618 = 289....almost 300 years
The union victory at Vicksburg was important for the north because the Union army captured the last Confederate stronghold on the Mississippi River, completing the Northern Strategy
