In addition to providing soldiers to the war effort in 1917, the united states also provided f. financial support g. moral support h. nuclear weapons i. democratic institutions

Let's go with answer "F" for "financial support" ... although the financial support that the USA gave to the war effort in 1917, along with the entrance of American troops into the war, provide a huge boost of moral support to the Allies as well.  
Britain had done most of the financial backing of the Allies in World War 1 up until 1916, when it ran out of money and needed to borrow from the United States.  The entrance of the US into the war in 1917 meant additional financial backing from the US side.  The idea was that these were loans to be repaid after the war.  In the post-war treaty, the Allies demanded financial reparations from Germany as a way of repaying the costs incurred.  The story of what happened as a result of the war reparations imposed on Germany ... well, that's another story for another time!