Which of the Following Is One of the Major Reasons

Multiple Choice

Which of the following is one of the major reasons the gold standard was abandoned? 

A)  The increased flow of gold from the U.S. into foreign central banks. 
B)  The competitive devaluation of currencies during the Great Depression. 
C)  The strengthening of the U.S. dollar due to the rise in productivity levels in the United States. 
D)  The United States unilaterally announced that the dollar would not be convertible to gold.