Explanation:

- Autocracy: In this system, power is concentrated in the hands of a single ruler. Legitimacy often comes from tradition or force, not from rational-legal principles.

- Oligarchy: This is the rule by a small group of people, with legitimacy usually based on wealth, family ties, or military control, not typically on rational-legal authority.

- Democracy: In a democracy, laws, procedures, and institutions guide power. Authority comes from a system of rules and legal frameworks agreed upon by the people—this fits the concept of rational-legal legitimacy as described by Max Weber.

- Gerontocracy: Rule by elders, legitimacy often comes from respect for age or tradition, not from rational-legal sources.

Correct answer: Option 3 - Democracy