The major conflict in this story is about the German occupation. This implies that the story revolves around the events and challenges faced by the characters during the time of German occupation. The conflict could involve resistance movements, struggles for survival, or the impact of the occupation on the characters' lives. The other options mentioned, such as Lise's death, food rationing, and Christian X falling from his horse, may be significant elements in the story, but they are not the central conflict.