The statement that best explains the Great Migration is:
Economic pull factors in the North were due to less European immigration and better job opportunities.
This theory highlights how the economic opportunities in northern cities became more attractive to African Americans who were seeking to escape the oppressive conditions in the South. The availability of jobs, especially during and after World War I when labor shortages occurred, served as a significant draw for many who migrated north.
The other statements either mischaracterize the dynamics of push and pull factors related to the migration or present inaccurate information regarding the movement's context.