Given the task definition and input, reply with output. 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'.

Sentence 1: Chad's neighbors had a large dog. Sentence 2: The dog would bark loudly outside every night. Sentence 3: The barking kept Chad from getting much sleep. Sentence 4: Chad asked his neighbors to do something about their dog. Sentence 5: The neighbors decided to keep their dog indoors at night. Choices: a. Barking Dog. b. The Attack.
a