The correct answer is C. The Thrirteenth Amendment.
Explanation
The Thirteenth Amendment is a United States state document by which slavery was prohibited since 1865. This document was preceded by the Emancipation Proclamation, a document issued by President Abraham Lincoln in the year 1863 during the Civil War for to declare slaves in some states of the country free, however, in areas controlled by the Union, the Emancipation Proclamation was not adopted, therefore, the president decided two years later to promote the thirteenth amendment to make the total abolition of slavery official in the country. So, the correct answer is C. The Thrirteenth Amendment.