The theme can be, a man is alone in the cold Yukon with nothing but a dog, and all odds are against him, including nature. A theme is an outline of the story by not getting into details
I think it's b? It would only be C if you caused the accident or if you were in the accident.
Lost generation is most likely referring to the young men that served in the military and lost their lives during the war, which left a huge age gap in many populations. The remaining population mostly consisted of women and men that were too old to serve or too young. All fit men between the ages of 18-45 ish were gone.