The correct answer is B) the war led to improved economic conditions.
The conclusion about the United States economy during WWII that is most clearly supported by the information of the graph is that the war led to improved economic conditions.
The graph expresses the relationship between the Gross Domestic Product and unemployment. As it is seen clearly in the graph, the Gross Domestic Product augmented since 1940. In that year, the GDP was 100 billions of dollars and by 1945 it was more than 200 hundred billion. Regarding unemployment, the rate was high in 1940. It was 14.6%. And by 194, it had declined to only 1.9%. So the conclusion about the United States economy during WWII that is most clearly supported by the information of the graph is that the war led to improved economic conditions.