(answer! ) which statements correctly define factors that contributed to the decline of the roman empire?
choose all answers that are correct.
a.
the empire split into three separate units, each ruled by a consul.
b.
a long period of peace throughout the empire led to a sense of overconfidence in rome.
c.
incompetent rulers placed huge tax burdens on the roman citizens.
d.
rome could not grow enough food and maintain a large enough army to fend off barbarian tribes.