Former slaves who contributed to the antislavery cause were
a. Horace Mann, Margaret Fuller, and Henry David Thoreau.
b. Josiah Quincy, Angelina Grimké, and Charles Finney.
C. Lucretia Mott, Walt Whitman, and Elizabeth Cady Stanton.
d. Frederick Douglass, Sojourner Truth, and Harriet Tubman.