The first choice has nothing to do with socioeconomic status and is therefore incorrect.
While choice two does possibly give an insight into the socioeconomic status of the family there is no sort of diversity mentioned at all.
The third choice is correct, it contrasts the author and love interest/friend's parents different socioeconomic status by saying that the author's parent felt hurt by the other parents shame of their less expensive home.
Choice four has nothing to do with socioeconomic status or diversity.
The answer is C.