Which of the following best describes how the Emancipation Proclamation was both a political and military strategy? A. It strengthened Lincoln's support from Northern abolitionists and also deprived the South of valuable labor.
B. It divided Lincoln's Northern political rivals and also organized African Americans into military units.
C. It allowed Northern slaveholders to keep their slaves, but required all slaves to work for the military during wartime.
D. It extended the overall power of the executive branch but limited the president's role as commander in chief of the military.