What is the term for a government ruled by a small group of people?

The term for a government ruled by a small group of people is "oligarchy." In an oligarchical system, power is concentrated in the hands of a few individuals or families who make decisions that affect the larger population. This small ruling group often maintains control over political, economic, and social institutions, exercising authority that can be derived from wealth, social status, military control, or other forms of power.

Oligarchies can take various forms, and the ruling elite may not always be accountable to the general public. This contrasts with a democracy, where power is derived from the participation of the many, or an autocracy, where a single individual has absolute power. In contrast, a theocracy is a system where religious leaders control the government, often interpreting laws based on religious doctrine. Thus, oligarchy specifically refers to the governance by a select few, making it the correct answer.