It represents Lady Macbeth's malaise and guilt awakening and driving her to insanity. In this scene, she "sees" blood on her hands, a metaphor for her guilt, and it cannot be washed off- the sin cannot be undone. After this scene, Lady Macbeth's strength runs out and is overcome with guilt to the point that she commits suicide.
The best answer is D because it has incorrect grammar, and uses slang/jargon and a dialect known as ebonics that was typically present in black communities during this time.
