The correct answer is C) His sense of high ideological purpose and "high and mighty" attitude toward other statesmen.
Woodrow Wilson's primary weakness as President and diplomat was his sense of high ideological purpose and "high and mighty" attitude toward other statesmen.US President Woodrow Wilson was a firm believer of isolationism foreign policy of United States, and maintain a policy of neutrality in European foreign issues, particularly regarding the US participation in World War I.
After the interception of Zimmerman's telegram and the sinking of the Lusitania ship by German U.boats, Wilson decided to ask the US Congress for a declaration of war against Germany and enter WWI. He previously had accepted to help France and Great Britain with weapons, supplies, and loans.
However, after the war, his diplomacy politic was not well received by the allies when they rejected to accept his "14 Point Plan" for peace after WWI.