The correct answer is B) several civil rights groups working together.
Selma became the center of the voting rights movement as a result of several civil rights groups working together.
We are talking about important civil rights groups such as the Student Nonviolent Coordinating Committee (SNCC) and the Southern Christian Leadership Conference (SCLC). Prominent civil rights leader Dr. Martin Luther King Jr was also invited and accepted to lead one of the marches from Selma to Montgomery.
The marches that started on March 7 and finished on March 25, 1958, marked a hiatus in the history of the civil rights movement because they attracted the attention of the public opinion in America. One of the results of the marches was that the support for voting rights increased.