Why were people angry about the kansas-nebraska act? a. it only granted popular sovereignty to eastern states. b. it reinforced the unpopular missouri compromise. c. it forced people to relocate to the great plains region. d. it stated slavery could be legal where it had been outlawed.

D. It stated slavery could be legal where it had been outlawed..

Explanation:

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.