Who were three significant black abolitionists prior to and during the civil war? harriet beecher stowe frederick douglass john brown harriet tubman josiah henson mary walker

From the given options these three significant black abolitionists prior to and during the Civil War

Frederick Douglass
Harriet Tubman
Josiah Henson

Although Mary Walker is also one who should be included in the list but as the question asked, the three are above mentioned.

The answer to the question is a.