How did darius able to maintain control of such a large empire select all that apply

A, B and C because Darius is the ruler of the empire and can do whatever he chooses.

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.