The correct answer is C.
The Plessy v. Ferguson case was solved with a landmark sentence issued by the US Supreme Court in 1896. It maintained the constitutionality of segregation laws, even for occupying public facilities, under the lemma "separated but equal". Everybody had the right of using public property, and those facilities, enjoyed separately by whites and blacks, had to be equal in quality.
It is considered as the one the most harmful decisions taken in the history of the US Supreme Court.