According to Walton and Rockoff, the Recession of 1937 and 1938

According to Walton and Rockoff, the recession of 1937 and 1938 could be attributed to ______ and ______.

A) the decline in world trade fostered by German and Japanese policies of self sufficiency, open market gold sales by the Federal Reserve.
B) increases in taxes, open market gold sales by the Federal Reserve.
C) increases in taxes, increases in bank required reserve ratios.
D) the decline in world trade fostered by German and Japanese policies of self sufficiency, increases in bank required reserve ratios.