The term "Oligarchy" (option 2) is used to describe a form of government where power and authority are held by a small group of individuals or a particular class. This group of people often makes important decisions and influences the policies and laws of the government, sometimes to the exclusion of the broader population.

 It is in contrast to "Monarchy" (option 1), where power is held by a single ruler.

 "Anarchy" (option 4), which refers to a state of disorder or absence of government.

 "Dyarchy" (option 3) is a system of dual government, typically with shared authority between two distinct entities, and is not the same as an oligarchy.

So, the correct option is [2].