Where did the sit-in movement start? who started it?

The Greensboro sit-in was a civil rights protest that started in 1960, when young African-American students staged a sit-in at a segregated Woolworth's lunch counter in Greensboro, North Carolina, and refused to leave after being denied service. The sit-in movement soon spread to college towns throughout the South.

Explanation:

either d or b, i'm not to sure. but my gut tells me it's prob going to be b