Answer:
a. the emergence of Martin Luther King Jr. as the leader of the Civil Rights movement.
Step-by-step explanation:
The historical Montgomery Bus Boycott of 1955-56 was a long 13 months duration mass protest that resulted from Rosa Parks' refusal to give up her seat for a white person. This refusal led to her arrest, which led to a mass demonstration and protests for the rights of blacks in America.
The protest was led by Martin Luther King who was the president of the Montgomery Improvement Association (MIA). And the Boycott ended after the Supreme Court ruled in their favor, declaring that segregation in the public transport system was unconstitutional. This victory then led to the greater prominence of Martin Luther King who emerged as the leader of the Civil Rights Movement.
Thus, the correct answer is option a.