Based on the map, what best explains the growing popularity of coffee in China?

Is there a passage that comes with this question or should i know this right off the bat, because if it is, i probably have short term memory loss or college is too stressful

The founder of the byzantine  empire  and its first  emperor,  constantine  the great,  movedthe  capital of the roman empire  to the city of byzantium in 330 ce, and renamed it  constantinople.  constantine  the great also legalized christianity, which had previously been persecuted in the  roman empire.