Can someone please help me with this? (I don't know if what I clicked was the answer but it doesn't let me unselect so I went with the top one)

where is the section with the question?

the second significant cause of the great migration was the desire of black southerners to escape segregation, known euphemistically as jim crow. rural african american southerners believed that segregation - and racism and prejudice against blacks - was significantly less intense in the north.

answer; (d) i believe that the correct answer is americans finally ran out of ammunition;

oil! is what i am assuming