How might china have benefited from building the great wall of china?

China greatly benefited from the Great wall of China because it protected the nation. Let me explain, China is surrounded on all sides by some obstacle expect where the Great wall of China runs. The Mongols used to attack villages on the outskirts of China and even further in because Mongolia was right next to China and China could not send enough soldiers to fight. So one of the emperors sent builders to build the Great Wall of China to protect China, especially from the Mongols.

Hope this helps

i believe 5 is correct answer