What is the connection between the civil rights movement and world war ii?

a. world war ii was the first war in which all units were integrated,
which showed that races could work together.

b. many african americans were interned in prison camps during the
war, which sparked several protests.

c. most african americans refused to fight in the war, which
triggered a series of protests that formed into a movement.

d. former african american soldiers wanted fair treatment,
especially given their service in war.