Why did robert y. hayne oppose tariffs? a. they cut down on competition for foreign goods. b. they expand roadways needed to develop the west. c. if the federal government could levy tariffs, then other policies that affected the states, such as abolishing slavery, could be next. d. they required participation by a nongovernment agency. e. they were unconstitutional.

The correct answer is option C. "If the federal government could levy tariffs, then other policies that affected the states, such as abolishing slavery, could be next".

Explanation:

Robert Young Hayne was an American lawyer that served in the United States government as a Senator, the governor of South Carolina and as a Mayor of Charleston. His political career included the opposition of the federal tariff bills of 1824, 1828, and 1832. He opposed these tariffs because he believed that if federal government could levy them they could abolish slavery which was a policy that affected the states. Hayne was always a supporter of slavery, and at one time he stated that federal government should let that the states handle the domestic concerns such as slavery.