Historians divide a particular duration of time with a distinct start and end date into:

A. a period.

B. an epoch.

C. a century.

D. a decade.

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.