Given the task definition and input, reply with output. 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: Pencil Case. Sentence 1: Ryan didn't have a pencil case. Sentence 2: He and his mom looked at the store. Sentence 3: There weren't any pencil cases left. Sentence 4: Ryan's mom sewed him a case that looked like a shark. Choices: a. She was finally able to slow him down, and make him stop chasing it. b. Ryan liked the shark pencil case.
a