Why is the concept of federalism filled with potential conflicts? What are some examples of this conflict?

More than any other aspect of U.S. government structure, federalism contributes significantly to innovation in state, local and national government alike.However, it's unlikely that the contemporary impacts of federalism in postindustrial America were fully anticipated by the framers of the U.S. constitution.  The Founders were driven to a much greater extent by a desire to strike a balance in political power between a nascent national government and the several pre-existing state governments than in promoting innovation and the capacity to adapt to ever changing socio-economic and environmental circumstances.  The adoption of a federal form of government at the outset of our nation’s history reflected an appreciation for the cultural heterogeneity that characterized the original thirteen states. As the intergovernmental relationships between the federal government and the several states have evolved over time, however, federalism in America has repeatedly proven to serve as an important institutional asset in the service of sustainability.

explanation:

with the profits from the european sales, merchants purchased europe's manufactured  goods, including tools and weapons. then the merchants shipped those manufactured  goods, along with the  american  sugar and rum, to west africa where they were bartered for  slaves.

it should be d or b but i'm sure it's d