Answer:I would say 3 is the answer. There was still plenty of racial tension Stateside; in fact, as AAs began serving in the military and coming back home, their renewed cries for equality began the early roots of the final stages of the Civil Rights Movement.
They also began protesting more actively because those who stayed Stateside and took up jobs vacated by servicemen felt angered at being forced to give up their jobs at the end of the war.
I hope I answer your question.