The correct answer is B. Wright wants to enhance the realism of the story for the audience.
The short story "The Man Who Was Almost a Man" was published in 1961. The technique of faithfully portraying the way the characters talk, their accent and informality, had been used to enhance realism much before that date. An example would be the writer F. Scott Fitzgerald, who already employed such style in his writing in the 1920's - for instance 'S'alright' instead of 'It's alright.'
That is what Wright does in the short story. Dave - an African-American who works at a farm - and the other characters have a very specific dialect. From its faithful representation in the story, a lot can be noted by the reader without much explanation being necessary: from the way they talk and the things they talk about, the time and setting, the social and historical context can be inferred. The very first dialog in the story is an example of that:
"Howdy, Dave! Whutcha want?"
"How yuh, Mistah Joe? Aw, Ah don wanna buy nothing. Ah jus wanted t see ef yuhd lemme look at tha catlog erwhile."
