I believe it's the first choice, '<span>"I don't know, I don't know," Becky wailed, resting her head on the steering wheel. "I just get so tired of failing."'
The line that most clearly creates the climax in the story is
"I don't know, I don't know," Becky wailed, resting her head on the steering wheel. "I just get so tired of failing."
Throughout the story, we know Becky is nervous, but we don't know why. We finally find out in this passage why Becky is so nervous. We find out later that she also doesn't want to be the oldest student without her license. Justin is able to calm her down by telling her that know one would need to know. She is then ready to take the test. Therefore, Becky telling Justin why she is nervous is the climax of the story.