Part A: The best answer is C. It creates a vivid and constant impression. The repetition of the lines about "momma" being in the bedroom with the door closed reinforces the emotional landscape of the poem, creating a sense of ongoing presence and impact.
Part B: The best answer is B. It emphasizes her loneliness. The repetition of the lines highlights the speaker's feeling of isolation and the lack of maternal support or presence, thereby deepening the sense of loneliness that characterizes her experience.