A system of government in which both states and the national government remain supreme within their own spheres, each responsible for some policy.

Answer: Dual Federalism

Explanation:

Dual Federalism is defined as state of politics in which power is split between state government and federal government. Both the governments are provided in separated with almost equal power and authorities to govern with equality. It is also known as layer cake federalism.

In this type of political agreement each government has enough power to rule with regulation in their acquired area without interference of other government.