"poor farming conditions in the north" although might have been a fact, was not a reason for war. The north had developed in other areas.
"the black nationalist movement" wasn't also the real reason. If anything, the movement would have wanted that the need for moving was non existent.
"the passing of the civil rights act of 1964" was what was meant to end segregation, not create it. So it's also wrong.
"segregation and racism in the south" is the correct answer. The south and the blacks have a long and harsh story of conflicts since the civil war and before, even.
