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: Linda loved to write her in diary. Sentence 2: She pledged herself that she would write in her diary everyday. Sentence 3: As Linda pulled her diary out of her drawer, she noticed it was open. Sentence 4: Linda then realized that someone was reading her diary. Sentence 5: She set a trap and found out her little sister was the culprit! Choices: a. Riding Buddy. b. Diary.

b