Answer:
Comparative advantage
Explanation:
This concept of economics is comparative advantage that means one country has advantage of producing same product at lower cost than other. In this question China has comparative advantage over USA,
This may be due to different reasons.
1. Population of China is greater than USA, that is why employees are willing to work on low salaries in China as compared to salaries are offered in the US.
2. China is comparatively better in manufacturing industry as of with USA.