The correct answer is B) federalism.
States are in charge of giving marriage licenses. The principle of government that is highlighted with this state power is federalism.
When we talk about United States politics, the principle of federalism refers to that the power of the government is shared by the state governments and the federal government.
This power functions under a system of checks and balances in which none of the branches of the government was more powerful than the other two. In the US government system, when federal law conflicts with state law, the federal law will win. This is included in the Constitution as the Supremacy Clause.