What significant event occurred at the Berlin Olympics that challenged Nazi beliefs?

The event at the Berlin Olympics that significantly challenged Nazi beliefs was the triumph of Jesse Owens, an African American athlete, who won multiple gold medals. The Nazi ideology promoted the idea of Aryan supremacy, suggesting that the so-called "Aryan" race was superior to all others. Owens' outstanding performance undermined this belief by showcasing extraordinary athleticism that surpassed that of the favored Aryan athletes. His victories in front of the Nazi regime not only contradicted their propaganda but also served as a powerful statement against racial discrimination, illustrating that talent and skill are not confined to a single race.

The other options do not align with this significant challenge to Nazi beliefs. While German athletes did perform well overall, this victory did not specifically confront Nazi ideology. The notion of hosting the Olympics in secret is historically inaccurate, as the games were held openly with considerable international attention. Lastly, although there were pressures on athletes to conform to Aryan standards, the Olympics included participants from diverse backgrounds, and not all were required to be Aryan, making this statement misleading in the context of the event's significance.