I DON'T HAVE MUCH TIME: 30 points: What event likely gave the United States more influence in post-war negotiations?
a. the dropping of atomic weapons
b. early participation in the war effort
c. sole claims concerning the liberation of Nazi death camps
d. a greater loss life than other Allied Nations

Exactly five years after the assassination of Archduke Franz Ferdinand—the event that tipped Europe into world war—the Treaty of Versailles was signed in Paris on June 28, 1919. The armistice signed on November 11, 1918 officially ended the hostilities, but the negotiations between the Allied victors at the Paris Peace Conference lasted six months and involved diplomatic delegations from over thirty-two countries. - Khan Academy

Explanation:

the answer is use of support