The correct option is this: DEMORALIZING THE NORTH WITH A VICTORY ON THE NORTHERN SOIL.
Most of the war has been taking place on the southern soil and the confederate forces has been forced into a defending position. Robert Lee tried to bring about a change of situation by deciding to launch an attack instead of continuously defending, he thus brought his forces to the northern soil just before the battle of Gettysburg in the hope of wining the north on their own land.