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: Jack made a ham sandwich. Sentence 2: As he went to eat it, he had a knock on the door. Sentence 3: He laid the sandwich down. Sentence 4: When he came back, his sandwich was gone. Sentence 5: He looked around and saw his dog finishing his sandwich. Choices: a. Necktie. b. Ham Sandwich.

b