You choose the topic before anything so you dont have to rush into picking a topic
I would say B. It inspired him to do it by the looks of things so A wouldn't make sense. C doesn't either. I don't think excited would make sense in the sentence, so B would make the most sense. Hope that helps.
Where the story took place. when the story happened.
Answer:
You could probably figure out that the boys in the story are English schoolboys, and were more than likely being evacuated from their home country to escape the possibility of atomic warfare. (Does this help?)
B.) Editing, hope this helps.