What was manchukuo?
a. part of the dutch east indies
b. a town along the burma road
c. puppet state after manchuria
d. an important japanese city

C. Puppet state after Manchuria

Manchukuo was a puppet state in Northeast China and Inner Mongolia. It was governed under a form of constitutional monarchy. The area was collectively known as Manchuria by Japanese and westerners. The Qing Dynasty of China designated the area as the “homeland” of the ruling family’s ethnic group or the Manchus. However, the Manchus never used the term “Manchuria” to refer to the place. The Japanese invaded the region in 1931.

I hope this helps.