Use the drop down menu to complete the sentence

The __________ was an advancement that contributed to economic prosperity in ancient
China.

The invention of paper was an advancement that contributed to economic prosperity in ancient China.

wrong

I apologize for the mistake. Could you please provide me with the correct options from the dropdown menu?

alright

Great Wall

Civil service system

Silk Road

Invention of acupuncture

The Silk Road was an advancement that contributed to economic prosperity in ancient China.

my thanks

You're welcome! If you have any more questions, feel free to ask.