Which event during the civil rights era did the most to focus the attention of white americans on the struggles of african americans in the south?

assassination of martin luther king, jr.
murder of volunteers during freedom summer
assault on freedom riders in alabama
assassination of medgar evers in mississippi

The assault on the Freedom Riders in Alabama really opened the eyes of whites because not only were blacks on the buses during the Freedom Rides, but there were also white riders who were attacked which made whites think, well if this is happening to people who are trying to help others gain equality, this must be some serious stuff.