The correct answer is C) The United States should stay out of the conflict.
The statement that best expresses the main idea of Wilson’s 1914 speech was "The United States should stay out of the conflict."
On August 20, 1914, United States President Woodrow Wilson delivered the "Message on Neutrality Speech." In this speech, President Wilson refers to the importance of the US maintaining a neutrality policy over the international conflicts in Europe, specifically, in the initial stages of World War 1. He asked US citizens to remain impartial too.