Democracy came to Greece by means of which of the following?

In the year 507 B. C., the Athenian leader Cleisthenes introduced a system of political reforms that he called demokratia, or "rule by the people." This system was comprised of three separate institutions: the ekklesia, a sovereign governing body that wrote laws and dictated foreign policy; the boule, a council of representatives from the ten Athenian tribes; and the dikasteria, the popular courts in which citizens argued cases before a group of lottery-selected jurors. Although this Athenian democracy would survive for only two centuries, Cleisthenes’ invention was one of ancient Greece’s most enduring contributions to the modern world.