The battle you are referring to is actually called the Battle of the Ironclads. In this battle, it was the Merrimac (from the Confederacy) versus the USS Monitor (from the Union). This was the first battle between iron-fortified vessels in the Civil War. This battle ended up in a draw but represented a new form of fighting that both the Union and Confederacy had to be ready for.
People helped hide fugitive slaves along the Underground Railroad and wouldn't turn them over to slave catchers.
Nikolai Novikov was the Soviet Ambassador to the United States in 1946-1947 and he prepared his telegram for Stalin and Molotov.
I'm pretty sure the answer is D :)