The words "beast" and "meanest reptile" emphasize the dehumanizing nature of slavery. By expressing a desire to be compared to a lower, non-human form of life, Douglass highlights the profound psychological torment and loss of humanity experienced by enslaved individuals. His longing for numbness and the absence of thought underscores the brutal reality of his situation, illustrating the deep anguish that comes with being enslaved. Thus, the correct answer is:
They emphasize the dehumanizing nature of slavery.