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: Billy always wanted to learn how to surf. Sentence 2: The only problem was he didn't know how to swim! Sentence 3: He went to the pool one weekend to learn but couldn't figure it out. Sentence 4: The life guard saw her struggling and gave him a free lesson. Sentence 5: He learned quickly and was soon on a surfboard! Choices: a. Injury. b. Surfing USA.

b