Which of the following is the best definition for feudalism?

Feudalism is the denomination of the predominant political system in Western Europe of the middle centuries of the Middle Ages (between the 9th and 15th centuries), and in Eastern Europe during the Modern Age, characterized by the decentralization of political power; based on the diffusion of power from the top (where in theory were the emperor or kings) to the base where local power was exercised effectively with great autonomy and independence by an aristocracy, called nobility.

necessary and proper clause. the congress shall have power to all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states, or in any department or officer thereof.