What Was the Single Greatest U

What was the single greatest U.S.contribution to the defeat of German forces on the battlefield in 1918?

A) the number and resilience of U.S. conscripts sent into battle alongside the Allies
B) the role of U.S. commanders, notably John Pershing, in devising a new strategy for defeating trench warfare
C) the large number of U.S. warships to the blockade of Germany
D) massive U.S. production of ships, tanks, and planes for the Allied war effort
E) the financial support the country was able to give to the Allies both before its formal entry into the war and afterward