Final answer:
Bruno and Gretal found it difficult to comprehend Auschwitz's true nature because the Holocaust's horrors were far beyond their previous life experiences and not widely understood or believed at the time, even by global leaders. So, the correct answer is option c.
Step-by-step explanation:
It is difficult for Bruno and Gretal to understand the true nature of Auschwitz because the horrors were beyond their previous experiences. Being children during World War II, their innocence and lack of awareness shielded them from comprehending the full extent of the atrocities committed at the concentration camps. The complexity of the Holocaust, coupled with the inherent disbelief by both survivors and observers of the systematic murder orchestrated by the Nazis, added layers of difficulty in grasping the horrors that were perpetrated.
Furthermore, information about the Holocaust was not widely disseminated or understood during the war. Reports of atrocities came as a shock to many, including global leaders, who struggled to believe the scale of the Nazi's genocidal policies. The Allied discovery of death camps further unveiled the grim reality of the Holocaust, a reality that was hard to conceptualize for those distant from it, especially children like Bruno and Gretal. So, the correct answer is option c.