Answer:
It serves to point out that basing the justification of slavery on the story of Ham is unsound.
Step-by-step explanation:
The Narrative of Frederick Douglass is a memoir of a slave named Frederick Douglass. In his memoir he shares his experience of slavery and his quest towards freedom from slavery.
In chapter 1, Douglass included the biblical allusion of God cursing Ham and his generation to be slaves. When enslavement was legalized in the 19th century in the South, people began to justify this enslavement by using this scripture and saying that God had made Ham's generation (Blacks) to be slaves by cursing them.
Douglass by including this scripture in his narrative points out that this justification is unsound as enslavement in the South was done of biracial people. In the South, white owners wouuld ra-pe black slaves and enslave the child born out of that. Douglass also was a biracial slave. Using this allusion, Douglass is stating tha justifying slavery based on the story of Ham is unsound.
Thus the last option is correct.