The Main Cause of Japanese Expansionism Seems to Have Been

The main cause of Japanese expansionism seems to have been

A) economic; Japan did not have the natural resources to sustain its industrialization and modernization.
B) ideological; the Japanese believed they were racially superior.
C) political; the Japanese needed foreign success to avert a revolution.
D) personal; the emperor was solely responsible.
E) the ultimate defeat of both China and the Soviet Union.