Final answer:
The Kansas-Nebraska Compromise is considered an uneasy compromise because it failed to effectively resolve the issue of slavery, intensified North-South tensions, and was plagued with enforcement disagreements, all contributing to the deepening rift leading to the Civil War.
Step-by-step explanation:
The reason why the Kansas-Nebraska Compromise would be called an Uneasy Compromise is d. All of the above. It led to increased tensions between Northern and Southern states (a), was not effective in resolving the issue of slavery (b), and there were disagreements over the enforcement of the compromise (c). The Kansas-Nebraska Act effectively repealed the Missouri Compromise's prohibition of slavery in certain territories, causing a surge in sectional conflict.
Northerners saw the extension of slavery into new territories as a violation of free labor principles, whereas Southerners believed they needed to expand slavery to preserve their lifestyle. The significant opposition from the North, including state legislatures opposing the bill and calls of a slave power conspiracy, as well as southern pressure on Senator Douglas and the Pierce administration to support pro-slavery provisions, exemplified the unease and controversy surrounding the act.
Ultimately, this compromise did not quell the underlying issue of slavery but rather acted as a precursor to the catastrophic sectional divisions that led up to the American Civil War, as it further deepened the rift between pro-slavery and anti-slavery factions.