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: I was walking outside one day. Sentence 2: I passed a watermelon stand. Sentence 3: A man was selling watermelons for 100 dollars each. Sentence 4: At first, I laughed at how expensive they were. Sentence 5: When I tasted how sweet they were, I bought five of them. Choices: a. Musical Disappointment. b. Expensive watermelon..

b