What was one effect of unrestricted German submarine attacks on shipping in World War I?

A. The United States led the Berlin Airlift.

B. British and French supplies never reached their troops.

C. The United States moved closer to declaring war on Germany.

D. The German navy became the most powerful naval force in the world.

The correct answer is C. One effect of unrestricted German submarine attacks on shipping in World War I was that the United States moved closer to declaring war on Germany.

Explanation:

Underwater warfare during World War I was in part a struggle between the German U-Boats and supply convoys across the Atlantic bound for Great Britain. The British and allied submarines carried out a wide spectrum of operations in the Baltic Sea, the North Sea, the Atlantic Ocean, the Mediterranean Sea and the Black Sea. Only a few actions took place outside the North Atlantic. Attacks by German submarines on Allied merchants gave the Americans a direct reason to enter the war in April 1917, after the sinking of the Lusitania and the interception of the Zimmermann Telegram.

B i believe. That may have been WWII though. their U-boats would take out french and english ships a lot tho.