What was the impact of the Montgomery Bus Boycott?

A. This peaceful action yielded quick and effective results, and the bus companies changed their policies immediately.
B. The bus company refused to hire African American drivers, even though the buses mostly served people of color.
C. Many African Americans became frustrated and riots occurred on the buses in Montgomery.
D. After over a year of boycotting, African Americans succeeded in desegregating the bus system.

D. After over a year of boycotting, African Americans succeeded in desegregating the bus system.