The most significant aspect of the Fourteenth Amendment, ratified in 1868, is that it granted citizenship to all persons born or naturalized in the United States, which included former slaves, and provided that no state could deprive any person of life, liberty, or property without due process of law, nor deny to any person within its jurisdiction the equal protection of the laws.
Thus, the correct response would be:
It granted African Americans in the United States citizenship and therefore voting rights.
While the amendment itself did not directly grant voting rights, it laid the groundwork for later amendments and legislation that would address voting rights.