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: Tom was a young boy with a piggy bank. Sentence 2: Tom wanted to fill up his piggy bank and buy a toy. Sentence 3: Tom placed coins in the piggy bank regularly. Sentence 4: Tom filled up the piggy bank. Sentence 5: Tom broke it to buy his favorite toy. Choices: a. HIV. b. Piggy Bank.

b