Answer:
B
Step-by-step explanation:
The choices of A, C and D are just wrong. B is the only answer that you can choose. It was what was set up.
A: America would never set up a government headed by an absolute monarch, but in Japan's case, Hirohito was not a bad ruler. He was more the spiritual head of the government. His last act of any meaning was to order the end of Japan's futile resistance in 1945. So America allowed him to retain his spiritual leadership, but nothing else and that begrudgingly.
C: The same reason for C not being true given in A is the one you would use here. America was terrified of a repeat where the military took power.
D: It would be a long day in winter before America would set up a government modelled like the one in Russia -- at least in 1945. Americans then believed that the best form of government was one like B.