Under the fourth seal, of the people of the earth would be killed by the sword, death, hunger, and the beasts of the earth.

i think its either b or c

explanation:

bloodiest single day of war   |   gettysburg

where the civil war ends for good   | appomattox court house

the first major land battle; south wins | bull run/manassas (va)

gives union control of the mississippi river |   vicksburg

lee’s first tactical defeat; big win for union |   fort sumter1

with lincoln's re-election |   atlanta

south wins

splits confederacy in two for the duration of the war,

antietam