What Was the Significance of the Battle of Antietam

What was the significance of the Battle of Antietam?

A) It convinced Lincoln to avoid talking about the possibility of ending slavery and instead portray the war as an effort to save the Union.
B) It greatly delayed anything resembling the Emancipation Proclamation, for free black soldiers had cost the Union the battle.
C) It was the least bloody of the Civil War battles, suggesting that the war had lost the support of many soldiers.
D) It was a turning point in that it revived northern morale and ended the Confederacy's hopes of gaining foreign alliances with Britain and France.
E) It led Lee to successfully capture Maryland and make it a key part of the Confederacy, as it was so much closer to the heart of the North.