The correct response is C: slaves outnumbered free people in the South.
Before the Civil War, in many Southern states, the enslaved population was indeed higher than the population of free people, with enslaved individuals often making up a significant portion of the total population in those states. While there were free people in the South, the prevalence of slavery was such that in areas like the Deep South, enslaved individuals constituted a majority or near-majority in certain contexts.