Answer: A) segregation.
Step-by-step explanation:
Brown v. Board of Education was a Supreme Court case in 1952 that removed the legal backing that a lot of Jim Crow laws establishing segregation had relied on.
The Jim Crow laws had relied on a policy known as ''separate but equal'' where a state could segregate public facilities so long as they provided equal facilities for both races.
The lawyers against segregation argued that these facilities were not equal and that states engaging in such were in violation of the 14th Amendment which stated that states must afford everyone in their jurisdiction equal protection.
The Supreme Court ruled in their favor the following year and stated that segregation in public schools was unconstitutional.