Which of the following is a shared cause of the downfall for both the Han and Roman empires? A.
Both empires grew too large to protect.

B.
Both empires were split into three kingdoms.

C.
Both empires were weakened by democratic protests.

D.
Both empires attempted to close the Silk Road.

I think it would be A. Both empire eventually became too big and that was there downfall.

Explanation:

"germany's geographic location was an advantage when it was on the offensive in the war because it was situated next to an extremely wide river, the rhine, which was difficult for the allies to cross."