The correct answer is A.
The Montgomery Bus Boycott was a social movement that protested against segregation in public transportation system in Montgomery (Alabama) and it emerged after the arrest of Rosa Parks.
Parks refused to give her seat to a white woman in the bus, when the bus driver required her to do so. As the area reserved for white passengers was full Rosa Parks, a black woman, was supposed to stand up and give her seat, in the black passengers area, to that white woman. She was returning home from work and she very tired, so she refused to stand up and was arrested for this motive.
