Answer:
B. Ships could hide at night
Further Explanation:
Brief WWI information
WWI was a global conflict that lasted from 1914 to 1918. The war was fought between the Allied Powers, which included the United Kingdom, France, Russia, and the United States, and the Central Powers, which included Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria.
What was the convoy system?
The convoy system was an Allied naval tactic employed in World War II to maximize the protection of merchant ships and minimize the exposure of these vessels to enemy attack.
Merchant ships would travel in groups, or convoys, escorted by military vessels. The use of convoys allowed the Allies to move large numbers of troops and supplies across the ocean while minimizing the risk of loss.
What were U-Boats?
U-boats were German submarines that were used in World War I and World War II. They were used to attack enemy ships and submarines, and to transport supplies and troops.