Question

what was the most significant use of german submarines during world war i?
deterring the expansion of the war
submarines were supposed to prevent a ground war in germany.
preventing the resupply of allied forces
reducing overall casualties

Explanation:

German U-boats in WWI primarily targeted Allied merchant ships to disrupt supply lines, aiming to cut off food, weapons, and resources to Allied forces. This unrestricted submarine warfare was a key strategy to weaken the Allies' war effort.

Answer:

preventing the resupply of Allied Forces