Answer:
C. Submarine attacks on American Ships
Step-by-step explanation:
Four days earlier, on April 2, President Woodrow Wilson addressed a joint session of Congress to request a declaration of war on Imperial Germany. Among his reasons for war was Germany’s failure to comply with its promise to halt unrestricted submarine warfare in the North Atlantic. Continued German attacks upon merchant shipping brought Wilson to insist that “warfare against commerce is a warfare against mankind.”