What is the climax in the boo Who Put that hair in your to tooth brush?

In "Who Put That Hair on My Toothbrush?" by Jerry Spinelli, the climax occurs when the main character, a young boy named Nick, confronts his sister about the mysterious hair found on his toothbrush. This confrontation escalates into a comedic and chaotic argument, revealing the underlying tensions and sibling rivalry between them. The moment serves as a turning point in their relationship, ultimately leading to a resolution and a deeper understanding of each other.