How was the Greensboro sit-in protest different from the approach of the NAACP?

The Greensboro sit-in, and those that followed, sparked a decade of civil rights demonstrations in the United States. That was a departure from the N.A.A.C.P.'s (National Association for the Advancement of Colored People), the leading civil rights organization at the time, which focused on ending segregation.

b - those executed came from every social and economic class

b is the answer i am assuming