What contributed to Athens losing the Peloponnesian War?

A devastating plague spread through overcrowded Athens early in the war, killing many people, including the leader Pericles. This weakened the city and contributed to Athens’s eventual defeat, so the correct choice is “Athens was overcrowded, and a plague spread through the city.” The Spartans did not win simply by breaking through Athens’s walls; Athens surrendered after later military and naval defeats.

AI-written and checked against the verified answer.