Please fast I need an answer. What was one major effect of President Lincoln's order in the passage?

Now, therefore I, Abraham Lincoln, President of the United States, by virtue of the power in me vested as Commander-in-Chief, of the Army and Navy of the United States in time of actual armed rebellion against the authority and government of the United States . . . I do order and declare that all persons held as slaves within [the Confederacy] . . . are, and henceforward shall be free; and that the Executive government of the United States, including the military and naval authorities thereof, will recognize and maintain the freedom of said persons.

A. Most of the border states left the Union and joined the Confederacy.
B. Thousands of enslaved people fled from Union territories to the West.
C. Great Britain decided not to recognize the Confederacy's independence.
D. Support for the Union war effort became more popular in the South.