Marco Polo traveled during the middle ages (AP period 3), for this the communication technology was not very advanced and Western Europe didn't really know the situation of East Asia and vice versa. When Marco Polo explained his travels to the Europeans of the greatness of China many Europeans decided to go and see for themselves if this greatness was indeed true. When the Europeans arrived in China they were very impressed and a new promotion of travel to China emerged, INCREASING China's economy.
C. It developed the world's largest pre-industrial city between 800 and 1431 CE.
C i hope it helped
Let me know if im right
honey can you write this in English ?