Which group used the legal system to challenge racial discrimination? unia naacp iww nwsa

Since being established in 1909 in New York City, the NAACP or National Association for the Advancement of Colored People became the United States' oldest and largest civil rights organization.

From its early days, it has served as a response to the violence against African Americans, and it played a major role during the civil rights era (1950s and 1960s).  

Answer is: Option B) NAACP

the roman army grew in size and became dominant in the mediterranean region.