Which of the Following Is an Example of De Facto

Which of the following is an example of de facto segregation?

A) In a medium-sized city, the black population lives almost entirely south of the railroad tracks while almost the entire white population lives north of the tracks.
B) Separate entrances to a restaurant are created for blacks and for whites.
C) Military units are separated by race into white units and black units.
D) The right to vote is restricted to those whose ancestors had the right to vote.
E) Private schools restrict admission to a single race.