It was during the First World War that a silent pilgrimage took its first steps within the borders of this country. ... It would not end
until the 1970s. ... Over the course of six decades, some six
million black southerners left the land of their forefathers and
fanned out across the country for an uncertain existence in nearly
every other corner of America. ...
-Isabel Wilkerson, The Warmth of Other Suns: The
Epic Story of America's Great Migration, 2010
What was a primary reason for the demographic shift described in this excerpt?
A)
Increased demand for sharecroppers in the North
B)
Limited economic opportunities for African Americans in the South
C)
Increased availability of manufactured goods in the North
D)
A lack of educational institutions for African Americans in the South