In this task, you're given the title of a five-sentence story, the first four sentences, and two options for the fifth sentence as a and b. Your job is to pick the sentence option that does not connect with the rest of the story, indicating your choice as 'a' or 'b'. If both sentences are plausible, pick the one that makes less sense.

Title: Stressful Lecture. Sentence 1: The teacher introduced us to a new chapter in the book. Sentence 2: He spoke too fast since the chapter was extremely long. Sentence 3: After a half an hour, the whole class became confused. Sentence 4: Some students decided to leave early. Choices: a. Although I was lost, I tried to remain in class and ask questions. b. Ona's teacher even said she was the best in the class!
b