The death of charlemagne and decline of his empire led to this system becoming a
widespread solution to a lack of central authority.
a anarchism
b feudalism
c confucianism
d communism

Feudalism

Explanation:

The people did not have a centralized power anymore and there fore did not have kings and queens but rather Lords and what not. The dominant social system in medieval Europe, in which the nobility held lands from the Crown in exchange for military service, and vassals were in turn tenants of the nobles, while the peasants (villeins or serfs) were obliged to live on their lord's land and give him homage, labor, and a share of the produce, notionally in exchange for military protection.

d

explanation:

he risk-return relationship. generally, the higher the potential return of an investment, the higher the risk. there is no guarantee that you will actually get a higher return by accepting more risk. diversification enables you to reduce the risk of your portfolio without sacrificing potential returns.

explanation: