Answer:
C De facto segregation is not mandated by law; de jure segregation is mandated by law.
Explanation:
De jure segregation is the one in which is mandated by the law. Examples of those are the Jim Crow laws and the Apartheid.
De facto segregation, otherwise, is not lawful, it just happens as a result of different things, like conservadorism, etc. One example of this are the segregated schools in the South in the past century.
The correct answer is letter C.