Which Statement Best Exemplifies the Concept of Social Injustice

Which statement best exemplifies the concept of social injustice?

A) I want to understand why I have failed to live up to my potential.
B) There is nothing I cannot achieve if I set my mind to it.
C) I am tired of looking across the street and seeing a quality of life I will never have no matter how hard I work.
D) I look at my neighbours who have done better than me, and I cannot figure out how I failed.