The United States Congress may pass laws, and they go into effect if the President signs the law. However, the Supreme Court can declare a law unconstitutional. This is an example of

Responses
A supremacy.supremacy.
B veto power.veto power.
C federalism.federalism.
D checks and balances.

D checks and balances.

D. checks and balances.

D: checks and balances.

Explanation:
Checks and balances is a system that ensures that no branch of government has too much power by allowing each branch to check the actions of the other branches. In this case, the United States Congress has the power to pass laws, but the Supreme Court can declare a law unconstitutional, thereby balancing the power of the legislative branch. This is an example of the checks and balances system in action.