Which of the following tended to divide rather than unify the people of acient Greece?

The city-states of ancient Greece, or poleis, tended to divide rather than unify the people. Each polis had its own government, customs, and military, leading to rivalries and conflicts, such as the Peloponnesian War between Athens and Sparta. Additionally, regional differences in culture and alliances further fragmented Greek identity. This division was exacerbated by the lack of a central authority, making unity challenging despite shared language and religious beliefs.