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: Landon was told by his mother to walk the dog. Sentence 2: Landon absolutely detested it because people yelled at him. Sentence 3: He took the leash, strapped it around her neck, and took her out. Sentence 4: A couple blocks away, thunder resounded and the dog became scared. Sentence 5: Landon and his dog retreated back toward the safety of their house. Choices: a. Instance. b. Thunderstruck.

b