Final answer:
Fredrik was incarcerated likely due to his perceived sexual orientation. His neighbor might have informed the Gestapo about his activities which led to his unjust arrest and imprisonment.
Step-by-step explanation:
The scenario presented strongly indicates that Fredrik's arrest was likely the result of his perceived sexual orientation. This unsettling event took place during a dark period in history: Nazi Germany, where homosexuality was criminalized and persecuted. In this historical context, it becomes apparent that individuals suspected of being gay were subjected to severe oppression, including incarceration in concentration camps.
The most plausible explanation, given this grim backdrop, is that a neighbor or someone in the community informed the Gestapo, the Nazi secret police, about Fredrik's activities, which ultimately led to his arrest. During this era, individuals could be arrested and detained without the necessity of a formal warrant or a fair trial. The mere suspicion of homosexuality was often enough to condemn someone to a life of persecution, discrimination, and unimaginable suffering.
Learn more about Nazi Persecution