The supreme couty decision in plessy v. ferguson (1896) affected african america by

Plessy v. Ferguson, 163 U.S. 537 (1896), was a landmark decision of the U.S. Supreme Court issued in 1896. It upheld the constitutionality of racial segregation laws for public facilities as long as the segregated facilities were equal in quality – a doctrine that came to be known as "separate but equal".

 "separated but equal"

b. martin luther king jr. wrote and spoke "i have a dream"

explanation:

i know this 100 percent is correct   b. is the best one. < 3

the answer to your question is a because laws act as guidelines as to what is accepted in society. without it there would be conflicts between social groups and communities. it serves as a norm of conduct for citizens.