Answer:
1 and 3.
Step-by-step explanation:
Germany was sinking ships while the U.S was supplying countries like England with food and weapons to cut off enemy supply lines, and then England intercepted the Zimmermann Telegram from Germany, which was a message Germany tried to send Mexico to convince Mexico to invade the United States. After England showed the U.S the telegram, they got upset and decided that was the last straw and finally declared war on Germany.