What statement BEST identifies a negative consequence of westward expansion in the years before the Civil War?

A significant negative consequence of westward expansion before the Civil War was the exacerbation of sectional tensions over slavery. As new territories were acquired and settled, the debate over whether these areas would permit slavery intensified, leading to conflicts such as "Bleeding Kansas." This division ultimately contributed to the polarization of the nation and set the stage for the Civil War. Additionally, the displacement and suffering of Native American populations due to land seizures marked a profound moral and ethical crisis.