What paradox of social injustice is presented in these lines from Countee Cullen's “From the Dark Tower”?

a. The hearing and speaking impaired are routinely victimized by others in American society.

b. Those who today enjoy power and prosperity may one day become subordinate to those they deem inferior.

c. The natural system of justice is unbiased, and all people are given equal opportunity to grow and flourish.

d. Those who enforce racial segregation are typically isolated groups in society.