Definitely B. it was very interconnected even connecting across the whole empire, to the Mediterranean Sea as well. A little background research is really interesting if you feel like it.
I would have to say it can't be A. there was much civil war, and lots of disputes with combining different ethnicity. People weren't too happy.
C seems like a likely answer, but I'm not quite sure how that increased trade.
I would think it not D because it would take over what it could, and what it could not, it didn't do much to. (basically they conuquered everything) ((almost)).
So that's why i'm thinking it is not D. If your gut says to do D, go with it. Usually your first answer is best. Hope this helps!
