The supreme court decision in the case of
plessy v. ferguson (1896) affected civil rights in
the united states by
(1) ruling that segregated public schools were
unconstitutional
(2) rejecting the legal basis of jim crow laws
(3) approving racial segregation in public
facilities
(4) strengthening the protections of the 14th
amendment

The Supreme Court decision in the case of Plessy v. Ferguson (1896) affected civil rights in the United States by 3. approving racial segregation in public facilities. The case was mostly focused on the legality of creating segregated train cars and the decision ruled that segregation in all places was legal provided all races be provided access to facilities "separate, but equal." 

Where are the options?