Final answer:
Sparta and Athens were rival city-states, mainly due to their military capabilities and contrasting political systems, with Sparta being an oligarchy and Athens the cradle of democracy. The correct option is A.
Step-by-step explanation:
The rivalry between Sparta and Athens, two city-states of ancient Greece, can be understood mainly through their military strength and differing systems of governance, representing the correct answer a) to the question provided. Sparta was known for its militaristic and austere way of life, as well as its oligarchic government.
In contrast, Athens was celebrated for its democratic system, art, and cosmopolitan lifestyle. This divergence fueled their ambitions and led to conflicts, manifesting most notably in the Peloponnesian War, where each city-state led opposing alliances in a struggle for dominance over the Greek world.
It is essential to note that while Sparta's preeminence on land and Athens's naval prowess were at the forefront, the underlying tension also involved strategic political alliances and differing cultural philosophies. Athens' Delian League and Sparta's Peloponnesian League were large-scale alliances that represented their struggle for regional influence.
Socially, their approach to life was starkly contrasting, with Sparta pursuing a strict, regimented society focused on military readiness, and Athens fostering an environment ripe for philosophical thought, artistic achievements, and civic participation.