Which best explains how the Kansas-Nebraska Act affected the Missouri Compromise?
It strengthened the Missouri Compromise by prohibiting slavery in states above the 36°30’ N line.
It overturned the Missouri Compromise by requiring slavery in states below the 36°30’ N line.
It overturned the Missouri Compromise by allowing the possibility of slavery in states above the 36°30’ N line.
It weakened the Missouri Compromise by allowing the possibility of slavery in states below the 36°30’ N line.