What type of trade especially helped Constantinople grow wealthy even as the Western Roman empire crumbled?

the answer would be:

b. race

economic advantages.

first of all, the south suffered a lot more damage then the north.

second of all, because the south has better weather, they usually stuck to farming instead of building up industries. the north, on the other hand, built up their industries much quicker and had a lot more factories then the south. also, more people lived in the north then in the south, allowing the north to quickly build up their armies. 

hope this