Q: 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: Teaching my friends to sing. Sentence 1: A few weeks ago I had to teach all my friends how to sing a song. Sentence 2: It was a song about how much fun we had at camp this year. Sentence 3: All my friends are terrible singers though. Sentence 4: We worked on the song all week. Choices: a. At the end of the week, my friends still were not good singers. b. Tom wondered why he hadn't done it earlier.
A:
b