The correct answer is C. "United over the Black Power Movement."
The Black Power Movement, by the middle of the 1960's, felt that a nonviolent means of causing change was no longer plausible. Instead, this movement focused on organizing with groups like the Black Panther Party. This movement and the organizations associated with it were not meant to cause outright violence. However, this movement believed that if an African-American person was being physically hurt or abused, they should fight back. This went directly against the ideas of the SNCC.