The Fifteenth Amendment to the US Constitution was intended to grant voting rights to freed slaves.
Option D
Explanation:
The Fifteenth Amendment stood as a ground for all citizens of the United States, they were enabled the right to vote irrespective of their race, stature before then and now and irrespective of color. The freed slaves known as the African Americans were given the rights to vote, this led to the suspection that these people do not need federal protection since they were acquired the right to be able to participate in the elections that were to be held in the states, for all citizens which now included the freed slaves into their constitution in the final amendment of it.