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: Tim had a favorite pen. Sentence 2: One day he couldn't find it. Sentence 3: He looked everywhere. Sentence 4: He went to ask his roommate and noticed he was using it. Sentence 5: Tim's roommate gave the pen back. Choices: a. Tired Passenger. b. Lost Pen.

b