Final answer:
Economic tensions between the North and South were primarily caused by differing attitudes towards tariffs, as the North wanted protection for their industries, while the South, which relied on trade and agriculture, opposed them.
Step-by-step explanation:
The economic tensions between the North and the South arose from their fundamentally different economies and conflicting interests. The correct answer is B) Tariffs. The Northern states, with their expanding manufacturing base, wanted protective tariffs to shield their industries from foreign competition. In contrast, the Southern states, which relied heavily on trade and cotton production, opposed these tariffs as their economy was not based on manufacturing but on agricultural exports facilitated by the labor of enslaved people. This difference in economic basis led to a regional conflict as tariffs imposed by the federal government often fell most heavily on the southern states, sparking resentment over perceived preferential treatment of the North. The Southern obstruction of efforts to increase tariffs and the protective measures advocated by Northern politicians exacerbated the sectional tensions, laying the groundwork for what would ultimately erupt into the Civil War.