1. Which best summarizes the migration process represented by the diagram?
(A) With European colonization and migration, positive aspects of
European culture spread across the globe in spite of obstacles.
(B) In the process known as step migration, migrants move from rural
to urban areas through a series of smaller moves, or steps.
(C) Each migration produces a counter migration of people returning
to their country of origin.
(D) The gravity model predicts that most migrants will move to the
closest metropolitan area in search of economic opportunities.
(E) Migrants leave their homelands because of push factors and move
to places with pull factors, but they often face barriers.