Which of These Did Not Help Japan Achieve Economic Prosperity

Which of these did not help Japan achieve economic prosperity after World War II?

A) Being able to purchase cheap oil for years after the war ended.
B) Being protected by the U.S.military and thus being able to invest what would have been spent on a military.
C) The high rate of savings among its citizens that allowed for loans and reinvestment in industry.
D) A declining population that meant less food had to be purchased.
E) A disciplined and skilled labor force.