The correct answer is C) the end of Athens's Golden Age.
The option that describes the effect of the Peloponnesian War is "The end of Athens's Golden Age."
The two most important city-states of Greece were Athens and Sparta. They engaged in the Peloponnesian War from 431 BC to 404 BC. After these city-states signed the Thirty Year Peace to maintain good relationships and recovering from the Persian Wars, difficulties arose and differences were insurmountable to the degree that the war was inevitable. Athens had a strong navy but Sparta was a warrior state where children were trained to be fierce warriors since their early years. Sparta won the war ending Athens's Golden Age.