What is the effect of the repetition of phrases similar to "i ain’t nothing but " by nancy and "i’m not " by jason throughout the story?

a. it reveals jason’s smug superiority as a five-year-old white boy over a middle-aged black woman
b. it highlights the racial divide in jefferson that is central to people’s identity and the town’s power structure
c. it shows jason’s preoccupation with discovering his identity and place in the town
d. it exemplifies nancy’s lack of self-worth as a result of how she is perceived and treated as a black woman