Answer:
A. The Germans sinking merchant and passenger u-boats was one of the primary reasons the United states entered the war. Many times these boats carried vital supplies. But the United States became outraged after learning that the Germans sunk a U-boat known as the "Lusitania" that was full of passengers civilians.
B. The Zimmermann telegram was a message sent from Germany to Mexico i attempts to drag Mexico into WWI against the US forces. The telegram stated that if Mexico joined Germany in defeating The US, then Mexico would gain their land they previously lost to the US. But, this telegram never made it to Mexico due to the fact that it was intercepted by The British. The British show the letter to the US, then the US saw this as a direct threat to them, dragging the US into the war.
