The correct answer is A) ethic diversity, trade, and pacifism.
Three factors that explain why the US wanted to remain neutral in World War 1 were ethnic diversity, trade, and pacifism.
President Woodrow Wilson wanted to maintain the neutrality of foreign policy in the face of the armed conflict in Europe. He did not want to be involved in World War 1 for the reasons mentioned above. However, the sinking of the Lusitania ship and the Interception of the Bismark telegram where Germany asked Mexico for help, made him change his decision. The United States entered World War 1 on April 6, 1917.
The other options of the question were B) ethic diversity, famine, and immigration. C) trade, economic depression, and ethnic diversity. D) trade, economic concerns, and pacifism.