Read the excerpt from Narrative of the Life of Frederick Douglass:

"We were all ranked together at the valuation. Men and women, old and young, married and single, were ranked with horses, sheep, and swine. There were horses and men, cattle and women, pigs and children, all holding the same rank in the scale of being, and were all subjected to the same narrow examination. Silvery-headed age and sprightly youth, maids and matrons, had to undergo the same indelicate inspection."

Which answer choice best states Douglass's purpose in this excerpt?

A. to demand payment from enslavers for their crimes
B. to show how children were treated better than elderly people
C. to compare his experience with that of other enslaved persons
D. to describe how people were degraded and treated inhumanely