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: I walked into Mr.Smith's room. Sentence 2: He showed where to sit and went over the rules of detention. Sentence 3: Instead of wasting time doing nothing, I did some homework. Sentence 4: I managed to finish most of it when detention was over. Sentence 5: Before I left, the teacher gave me a warning. Choices: a. Surprise. b. Day in Detention.

b