The correct answer is B.
The Neutrality Acts were enacted between 1935 and 1939 to cope with the geenral disillusionment after World War I, and triggered because it was believed that the US participation in WWI started due to the economic involvement of the country with the European belligerents: loans, trade agreements, etc.
After the start of WWII, changes were introduced in the Neutrality Acts in 1939 by the government of President Roosevelt, that changed the conditions in which the US could sell munition and other commodities to the belligerent countries (banned before).
Two years later, the neutrality attitude of the US disappeared and the country joined the Allied Forces. By this time, the US enjoyed a very profitable trade surplus.