Which of the Following Statements Describes the Significance of the Battle

Which of the following statements describes the significance of the Battle of Antietam?

A) More Confederate troops died in this battle than in the entire rest of the war.
B) It was the first definitive Union victory in the eastern theater of the war.
C) McClellan's battle plans fell into Confederate hands before the battle took place.
D) Lincoln removed McClellan from command after the battle for his timidity.