Definition: In this task, you're given five sentences, numbered 1 through 5, and two options a and b for possible titles for the story. Your job is to choose the title that better fits the story. Indicate your choice by 'a' or 'b'.
Input: Sentence 1: Walker enjoyed biking every day. Sentence 2: He biked so much that his bike broke down. Sentence 3: He had to get a lot of expensive repairs done. Sentence 4: After the bike was repaired it was as good as new. Sentence 5: Walker then biked with his friends as well. Choices: a. Biking. b. Arm.

a