What was the role of the Emperor in the new government of Japan after
WWII?

Hirohito (1901-1989) was emperor of Japan from 1926 until his death in 1989. He took over at a time of rising democratic sentiment, but his country soon turned toward ultra-nationalism and militarism. During World War II (1939-45), Japan attacked nearly all of its Asian neighbors, allied itself with Nazi Germany and launched a surprise assault on the U.S. naval base at Pearl Harbor. Though Hirohito later portrayed himself as a virtually powerless constitutional monarch, many scholars have come to believe he played an active role in the war effort. After Japan’s surrender in 1945, he became a figurehead with no political power.

Hirohito as Emperor and the Rise of Japanese Militarism

When Hirohito assumed the throne, a universal male suffrage law had just passed, and political parties were near the height of their prewar powers. However, a plunging economy, rising militarism and a series of political assassinations soon caused a crisis for the pro-democracy movement. Hirohito, who as emperor was the nation’s highest spiritual authority and commander-in-chief of the armed forces, essentially fired the prime minister in 1929. The next prime minister was shot and mortally wounded, and in 1932 yet another prime minister was assassinated by naval officers upset about a treaty limiting the number of Japanese warships. From then on, almost all prime ministers came from the military rather than from the political parties, which were disbanded altogether in 1940. More political violence occurred in 1935, when a lieutenant colonel slashed a general to death with a samurai sword. And in 1936, over 1,400 soldiers mutinied in Tokyo, seizing the army ministry and murdering several high-ranking politicians.

Ithink the answer you are looking for is (b).