In creating a new U.S. government, it was "A. The Virginia Plan" that proposed that the elected members of lower house would select the members of the upper house, since this would have favored the larger states.
D is your answer. it gives a more specific answer than the other choices, plus it is true. Slavery has been around since Jesus time, so that's way longer than the 1500s
Research and publication of works on social and labour issue
I don't actually know this. But, I think that it was Lincoln. Then the Amenstapation proclamation was created. BTW, I probably spelt Amenstapation wrong.
1. The North had a bigger population.
2. The South had a better military advantage.