Answer:
(C) with the ratification of the 13th Amendment to the Constitution
Explanation:
As a border state, Kentucky was excluded from the Emancipation
Proclamation, which declared the end of slavery for those living in
states in rebellion against the United States effective January 1,
1863. This was an important consideration for Lincoln, as he needed to
keep the border states from joining the Confederacy while still
convincing European nations to stay out of the war. The 13th Amendment,
ratified in December 1865, officially ended slavery throughout the U.S.