Why was the kansas-nebraska act difficult for northerners to accept? a. it identified slaves as being property and not human beings. b. it denied abolitionist conventions within the kansas and nebraska territories. c. it opened slavery in territories that many had thought would stay free. d. it required northerners to acquire slaves through the atlantic slave trade.

Correct  C. It opened slavery in territories that many had thought would stay free.

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.