In 1917, Germany, determined to win its war of attrition against the Allies, announced the resumption of unrestricted warfare in war-zone waters. Three days later, the United States broke diplomatic relations with Germany, and just hours after that the American liner Housatonic was sunk by a German U-boat.
Hey, it's b because slavery was the main thing that supported the South's economy - hope this helps :)
Any options to help answer your question?
I think B is the appropriate answer among the others. Hope this helps :)
