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: New Joke. Sentence 1: Lewis told his friend a joke. Sentence 2: His friend was offended by the joke. Sentence 3: Lewis asked his friend to help change the joke. Sentence 4: His friend suggested a change. Choices: a. Matthew's friend laughed in surprise in seeing Matthew at his home. b. Lewis told his friend a new joke.
Output:
a