The Allies declared after the Potsdam Summit that the only surrender they would accept from the Axis powers was an unconditional surrender, that is, one without any conditions attached it to be the surrendering party.
Truman was fully briefed about Japan's resolve and had to weigh that in deciding where and how to force Japan into an unconditional surrender. If they had not dropped the bomb, preparations were being made to land an invasion force.
Personally, I would choose C because you could talk about the first time cars came out, when they were first used on the roads, and maybe relate to other countries (some came before, others after!) and who invented it-some background info on the inventor of the first car, etc.
