The correct answer is:
C. Natural barriers to travel contributed to the development of distinct cultures among the city-states.
Ancient Greece was characterized by its mountainous terrain and numerous islands, which acted as natural barriers. These geographical features hindered communication and travel between different regions, leading to the establishment of independent city-states (polis) that developed their own distinct cultures, political systems, and identities. Each city-state, such as Athens, Sparta, and Corinth, had its own unique characteristics, which were shaped by their specific environments and interactions with neighboring areas.