Invasions by Barbarian tribes. ...
Economic troubles and overreliance on slave labor. ...
The rise of the Eastern Empire. ...
The most important reason for the collapse of Rome was the failure to actually integrate what they conquered. When Roman soldiers conquered new lands, it was rare that they ever attempted to force their culture, ideals, or laws upon the natives and barbarians. Thus, when the Empire began suffering internal struggles, the natives they had conquered decided to take action, which lead to the swift collapse by barbarian invasion from all sides. It's hard to pick a LEAST important reason, seeing that there were many of them, but I suppose a contender would most likely be the common refusal of the Empire to even acknowledge that barbarians were rising. On the outer edges of their territory, in places like Gaul and Morocco, the Roman government was reluctant to even recognize the threat of the barbarians, thinking that even accepting that these barbarians were causing trouble would weaken their prestige in the public eye.
C) the biography of a pharaoh
Answer:
A cannon and soldiers on horseback.
Explanation:
From the description given by the Aztecs, it is likely that what they are seeing for the first time is a cannon and soldiers riding on horseback.
The Aztecs described it as "a thing that a ball of stone comes out of its entrails" and if it were aimed at a tree, "it shatters the tree into splinters", almost as if "the tree had exploded from within" which is a very good description of a cannon.
Also, they described something about men "dressing in iron" and their "deer carrying them" anywhere they wanted to go, which is a good description of armor-wearing soldiers on horseback.