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: My son was outside playing. Sentence 2: His best friend came by the house. Sentence 3: They went off on an adventure. Sentence 4: They were gone for quite some time. Sentence 5: They came home before dark. Choices: a. Best friends. b. Chivalry.

a