An oligarchy is best defined as

rule by a few in a government or organization.

Oligarchy restricts the people who can be in control or rule by restricting requirements to the rule.

In a oligarchical government, the elite are typically the only that can rule. In many early democracies, the citizenship was restricted to the educated and wealthy and therefore were oligarchies with democratic powers. Many organizations are run as an oligarchy with board members in charge of decision making.

your answer would be (a)

omg i dont know oops sorry