How had kansas-nebraska act propose to deal with the issue of slavery?

The Kansas-Nebraska Act proposed that new states should be allowed to vote on whether or not they would allow slavery.

Explanation/context:  

Senator Stephen Douglas proposed the bill that became the Kansas-Nebraska Act as a way of getting southern support for Nebraska  statehood.  Douglas was seeking to bring Nebraska into the Union in order to bring those lands under government authority and lay the groundwork for building a Midwestern route of transcontinental railroad that would run to Chicago and benefit his state (Illinois).  The compromise to gain support from the South was to create two states, Nebraska and Kansas, and allow voters in those areas to choose whether they'd be slave or free. The thought was that Kansas might end up as a slave state and Nebraska as a free state, thus maintaining the balance between free and slave states.

The Kansas-Nebraska Act was enacted by Congress in 1854. It granted popular sovereignty to the people in the Kansas and Nebraska territories, letting them decide whether they'd allow slavery.  In essence, this made the Kansas-Nebraska act a repeal of the Missouri Compromise of 1820, which had said there would be no slavery north of latitude 36°30´ except for Missouri.

After the passage of the Kansas-Nebraska Act, pro-slavery and anti-slavery settlers rushed into Kansas to try to sway the outcome of the issue, and violence between the two sides occurred.  The term "bleeding Kansas" was used because of the bloodshed.  Kansas and Nebraska ended up as free states, but the Kansas-Nebraska Act had allowed the possibility that slavery could become slave states.

the vast majority of ballots have been counted nearly two weeks after one of the biggest political upsets in modern u.s. history catapulted donald trump to the presidency.

estimates show more than 58 percent of eligible voters went to the polls during the 2016 election, nearly breaking even with the turnout rate set during the last presidential election in 2012, even as the final tallies in states like california continue to be calculated, according to statistics collected by the u.s. elections project.

but among those figures were stark contrasts in key states that swing the election to trump — in ohio, wisconsin, iowa, michigan and elsewhere — indicating the president-elect’s leap from long-shot candidate to the most powerful political position in the world may have happened in part because of apathy toward hillary clinton’s candidacy, especially among the democratic base, several political scientists and organizations monitoring voter turnout told the pbs newshour.

while clinton is leading the popular vote by more than 1.5 million over trump as of sunday, she trails president obama’s 2012 totals by more than 2 million ballots — a chasm that may have cost her the election, said david becker, co-founder of the center for election and innovation and research.

“several million voters didn’t come out to vote,” becker said. “which is telling me that this idea of the trump wave, a huge number of voters shifting over to trump, is certainly not the story.”

d is the right answer