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.  c.  it overturned the missouri compromise by allowing the possibility of slavery in states above the 36°30’ n line.