The correct options are
A Victor, a Scottish by birth, studying in Australia.
C Smith and Ravi having dissimilar religious views.
D John, a Black-American, staying in America with the White people.
Social differences are situations when people are put to a disadvantage based on gender, caste, race, etc. Social differences by birth cannot be controlled because a person cannot choose to be born in a community, place or race. Other social differences occur due to the choices people make, for instance, education, profession, etc. All these social difference leads to the formation of social groups.