Which victory for the Confederates convinced General Lee to march into the North to try to begin a campaign in the North to work towards ending the war?

Select one:
a. Gettysburg
b. Chancellorsville
c. Vicksburg
d. Shiloh
I think B. but idk

NOT A, he lost

NOT C, That was out West and lost to boot
NOT D , That was not in Lee world either
SO B :) which he won