Which governmental structure allows for a unifying system to balance relationships between a nation's central government and its states?

The correct answer is federalism. This system of government is designed to create a balance of power between a central authority and various regional or state governments. Under federalism, both the central government and state governments have their own powers and responsibilities, which allows for a more tailored governance that can address local needs while still maintaining a strong national framework.

In a federal system, the constitution typically outlines the powers that are exclusive to the national government, those that are reserved for the states, and areas where both levels of government can have authority. This separation of powers helps to prevent any one level of government from becoming too dominant and encourages cooperation between the states and the central government.

In contrast, a unitary system centralizes power primarily in the national government, leaving states or regional authorities with little autonomy. A confederation is a loose alliance of independent states that delegate some powers to a central authority while retaining most of their sovereignty, which can lead to weak governance. Authoritarianism represents a governance style where a single entity or leader holds significant power, often at the expense of individual freedoms and democratic processes. These structures do not provide the same balance and collaborative relationship found in federalism.