Answer: A. It emphasizes the theme of sorrow and melancholy in the poem.
Explanation: Repetition is a literary device, that consists in the repetition of words, phrases, structures or sounds, in order to produce rhythm or to emphasize in a specific idea in the text. In the given excerpt from "The Weary Blues" we can see an example of repetition of the phrase "Ain't got nobody" in this example, the repetition of that expression helps to emphasize the theme of sorrow and melancholy in the poem.
