Question

people who wanted to end slavery were called
freemans bureau
naacp
abolitionists
northerners united against slavery

Explanation:

The question is about people who wanted to end slavery. Abolitionists were individuals who advocated for the abolition (ending) of slavery. The Freedman’s Bureau was a post - Civil War agency to help freed slaves, the NAACP was founded much later for civil rights (not primarily about ending slavery in the pre - Civil War/early abolition era), and "Northerners United Against Slavery" is not the standard term. The correct term for those wanting to end slavery is abolitionists.

Answer:

B. Abolitionists