Question

what event was planned to solve the problem identified by admiral nagano?
A) attack on Pearl Harbor
B) invasion of the Soviet Union
C) dropping of the atomic bomb
D) use of v-2 rockets against cities

Answer 1

Japan skirmished with Soviet forces but their defeats during the battles at Khalkin Gol in '39 convinced the leadership that "striking north" was a bad idea and refocused their efforts against China instead, so (B) is out. Japan also didn't have any atom bombs (nor was even close to getting one), so (C) is definitely out, and only the Germans used V2 rockets so (D) is also out.

That leaves only (A) as the answer that makes sense. Japan needed a freer hand in their plans against Southeast Asia and Pearl Harbor was meant also to crush American morale. Incidentally, Nagano was against a surprise attack but was eventually convinced to approve it by Yamamoto.