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 loved playing with building blocks. Sentence 2: He built a toy building that was taller than he was. Sentence 3: He needed a chair to reach the top. Sentence 4: His baby sister cam and knocked it over. Sentence 5: Tim was frustrated but happy about how he spent his day. Choices: a. Building Blocks. b. The Tulips.

a