How did geography affect greek and persian civilizations differently during the classical era? a. access to major waterways allowed the greeks to easily conquer neighboring civilizations, but persia had difficulty moving large armies across its territory. b. flooding caused by seasonal rains prevented greeks from forming strong cities, while persians were able to grow large urban areas. c. waterways and mountains led to the formation of separate city-states in greece, but vast open plains led to a unified empire in persia. d. hot, dry weather conditions prevented population growth in persia, while fertile soil in greece led to large populations.