The correct answer is C.
Plessy v. Ferguson was a landmark decision (1896) of the U.S. Supreme Court. It upheld the constitutional right of racial segregation laws for public facilities. It is known as the 'separate but equal' doctrine, meaning that the separated facilities had to be equal in quality.
Justice Henry Billings Brown stated in his verdict that separation does not necessarily imply any inequality and that the segregation laws do not imply that a particular race was inferior.
The verdict upheld the constitutionality of racial segregation as long as the facilities were equal in quality.