B, because back than there was an equal amount of slave states and free states. they banned slavery only in the free states because it was not allowed , they kept it in the slave states , kept it as in kept slaves in slave states.This made a lot of people who wanted to ban slavery mad.
They could not ban slavery in slavery in any of the slave states. After this ruling, slave states have celebrated and labeled the constitution as a pro-slavery document. This also angered abolitionists who wanted to ban slavery
