As a Consequence of the Battle of Shiloh

As a consequence of the Battle of Shiloh,

A) General Grant realized that a complete conquest of the South would be necessary to save the Union.
B) Lincoln gave command of Union forces to General Ulysses S. Grant, replacing General George McClellan.
C) General Robert E.Lee suggested that President Davis open peace negotiations with the Union.
D) McClellan's forces were forced to retreat to the Potomac, thus saving the Confederate capital at Richmond.