Why did the greeks join forces? which greeks provided the army? the navy?

Sparta and other city-states joined forces against Athens to fight the Peloponnesian War. The factors which led to the decline of the Persian Empire were that the army was weakened after losses to Greece and rulers disagreed about who should have power.

b, the anti immigrant fervor

when in doubt choose c

it's what my teacher told my class when we were going into psats