The correct answer is B) that the war would cost American lives.
What most Americans understood before their country entered World War 1 was that the war would cost American lives.
Although sometimes war is necessary, it is always a painful moment for the life of a country. War means people dying, and that is a terrible thing. The United States foreign policy tried to maintain the neutrality in world conflicts until many incidents provoked that the United States entered World War 1. American citizens knew that entering the war meant sacrifices. the potential loss of the lives of thousands of soldiers, painful moments for their families, and a period of sorrow and sadness.