You will be given a definition of a task first, then some input of the task.
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: The Hard Class. Sentence 1: Gretchen was enrolled in a class in college. Sentence 2: She was doing badly in the class. Sentence 3: Gretchen decided to withdraw from the class. Sentence 4: The next semester, Gretchen had a lighter work schedule. Choices: a. But at least Ian got twenty dollars for it. b. She decided to try taking the class again.
Output:
a