Please help?! Under the system of feudalism, lords and kings could simply require their vassals to fight in their defense, and the knights were bound by chivalry to remain loyal. How did the city-states of the Renaissance fund their wars?

They required each citizen to commit to several years of military service.
They forced their citizens to pay most of their wages in taxes.
They sold sections of the city to pay for weapons and soldiers.
They borrowed money from their citizens using bonds, then hired an army.

Question

Please help?! 	Under the system of feudalism, lords and kings could simply require their vassals to fight in their defense, and the knights were bound by chivalry to remain loyal. How did the city-states of the Renaissance fund their wars?
 	
	They required each citizen to commit to several years of military service.
	They forced their citizens to pay most of their wages in taxes.
	They sold sections of the city to pay for weapons and soldiers.
	They borrowed money from their citizens using bonds, then hired an army.