Answer:
A. Mountainous terrain and many islands.
Explanation:
The physical geography of Greece included large amounts of islands, and the mainland having large amounts of mountain ranges that made traversing between cities harder. This led to Greek cities to become more independent and in turn becoming city-states, in which the cities are independent and govern themselves. This is shown throughout Ancient Greek history with independent city-states having quarrel fights (particularly between Sparta and Athens) and only allying themselves in face of foreign invasion (particularly during the expansion of the Persian Empire into Greek lands).
Learn more about Ancient Greece, here:
https://brainly.com/question/11857441 - Ancient Greek questions.
Edit 1: Insert Greece mountain geography
Insert Greece City State locations