Answer:
D. Douglass believed the Constitution could be used to abolish slavery.
Step-by-step explanation:
Frederick Douglass was born a slave in Maryland where he learned to read. The knowledge he received from the books, essays, newspapers, etc. were keys to help him develop his opinion about freedom, slavery, and human rights, that, once he had escaped to the North, led him to become a leading orator, writer, and leader in the abolitionist movement, and advocator of equality and human rights. So, as an abolitionist, Douglass believed the Constitution could be used to abolish slavery.