The 1955-1956 African-American Boycott of Segregated Buses in Montgomery, Alabama

The 1955-1956 African-American boycott of segregated buses in Montgomery, Alabama eventually led to

A) Supreme Court affirming a lower-court decision outlawing segregation of public transportation.
B) election of a black mayor in Montgomery.
C) defeat of Democratic incumbents throughout the south in the 1956 election.
D) voluntary concession by white leaders in Montgomery to integrate buses.
E) collapse of the civil-rights movement when African-American leaders were unable to deliver on their promises of social change.