Why did lincoln feel it was important to identify himself not only as president but also as commander-in-chief of the armed forces at the time of the emancipation proclamation?

I literally taking the test now and this is what I put:

The Emancipation Proclamation was an Executive Order, making it extremely reasonable for Lincoln to show his authority to issue it by noting he is President of the United States. By adding that he is Commander-in-Chief emphasizes that the Emancipation Proclamation is a military measure designed to restore the Union and to return the Confederate States to the Union. He offers not to free the slaves of any state which will voluntarily return to the Union. He also proposes compensated emancipation for slave owners willing to sell their slaves to the Federal Government.

make law

explanation:

i think it would be c.

hope i'm correct

explanation: