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: The family was at the park. Sentence 2: A loud thunder clap rang out. Sentence 3: The family watched the cloud roll in. Sentence 4: A tremendous storm began. Sentence 5: The family scrambled to shelter. Choices: a. thunder. b. Smelly house.

a