The correct answer is C.
The victorious allied powers occupied Japan at the end of WWII, under the command of General Douglas MacArthur that adopted the title of Supreme Commander of the Allied Powers. In this occupation, denominated the Operation Blacklist, the URSS played no role (in opposition to its active role in the occupation of Germany).
Under General MacArthur's leadership, Japan was transformed into a parliamentary democracy that implemented the provisions of Roosevelt's New Deal for the economic recovery. Moreover, a policy of disarmament was fostered, including a "peace clause" in the new Japanese Constitution enacted after WWII, through which Japan renounced to maintaining any armed forcers.