The statement below is from the Supreme Court decision in Dred Scott v Sandford (1857). "We think... that [African Americans] are not included and are not intended to be included under the word "citizen" in the Constitution. How did this decision contribute to the outbreak of the Civil War four years later? a It destroyed existing compromises that had kept the nation together despite differences over slavery. b It helped abolitionists in their campaign to challenge the Fugitive Slave Law. c It led enslaved African Americans to rebel in major Southern cities. d It resolved the issue of the extension of slavery in new western territories.