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: Tom hadn't heard his upstairs neighbor move in a long time. Sentence 2: He hadn't seen him outside either. Sentence 3: After a while he went to knock but nobody answered. Sentence 4: He called the authorities just to make sure. Sentence 5: Tom's neighbor had moved out without telling anyone. Choices: a. Gloves. b. Quiet Neighbors.
b