Answer:
The approval of protective tariffs on manufactured goods
Step-by-step explanation:
The acceptance of precautionary and preventive tariffs on the produced goods was the event that gave a hint to develop the belief among the Southerners regarding the danger their economy was facing. The tariffs imposed on these goods led to a significant hike in the prices of the goods and now they were compelled to pay extra for any kind of imports especially the ones from Europe. This was not only unjust and inessential. Thus, the Southerners came to know about the potential threat to their economy and they started to oppose it.