Which of the following factors did not play a direct role in Japan's growing militarism in the 1930s?

a) Desire for an East Asia Co-Prosperity Sphere centered on Japan
b) Anti-immigration laws that blocked Japanese immigration to western nations
c) Trade barriers put in place by western nations in response to the Great Depression
d) The growing strength of Nazi Germany's navy and merchant marine fleet
e) The demise of a multi-party political system in the early 1930s and the growing political power of the Japanese military