What caused the growth of cities?

• A. War
• B. Religion
• C. Isolation
• D. Surplus food

Answer: (D)

Surplus food fuels urban growth because it lets a community sustain more people than just those needed to farm for daily meals. When farming yields more than what a household needs, not everyone must stay tied to growing food, freeing people to specialize in crafts, trade, administration, and leadership. Those specializations create economic activity and social organization that cities rely on, along with the need for shared infrastructure like granaries, markets, and governance. A stable food supply also supports storage for tough times and the accumulation of wealth, which in turn attracts people from the countryside to urban centers. While war, religion, and isolation can influence cities, they don’t by themselves create dense, permanent settlements the way a reliable food surplus does.