Well which of what there is no answer choices. If I had to guess without the multiple choice questions it would be because all of the soldiers came home from WW2 seeking a job in a very crowded workforce.
World War I was really the fist "total war" in the sense that practically all available manpower and resources were used to fight the enemy. This meant that there were no "breaks" and very few rules to the fighting.
It reaffirmed the good diplomatic relationship the United States and France had established prior to Statue of Liberty being built. Moreover, it recognized the independence the French helped the U.S. to achieve in the Revolutionary War and the hardships the two countries shared during and after the war.