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: A friend asked Bill to watch his dog while he was gone. Sentence 2: The dog was left at Bill's house. Sentence 3: The dog got out of Bill's yard and disappeared. Sentence 4: Bill's friend came back early to look for the lost dog. Sentence 5: The dog was found in a neighbor's garage. Choices: a. Lost Dog. b. Flight of the Bumblebee.

a