How was tea important to china's economy?

Tea was boasted to be a medicinal feature from China and helped to open up the Silk Road which opened up China to West Asia and Central Asia. Eventually word spread to Europe and China's economy was opened to trade to Europe. In exchange for massive amounts of silver, China traded tea, porcelain, and silk to Europe. 

Idon’t see any choices but i think it’s because it’s the work for that class and so the teacher doesn’t get confused

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