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 children laughed as it started raining on them. Sentence 2: They splashed about and started throwing mud at each other. Sentence 3: Nora looked aghast through the door and prepared to yell at them. Sentence 4: She paused when she realized how much ridiculous fun they were having. Sentence 5: Nora decided to laugh at their antics and to join them, instead. Choices: a. Karen's Trip. b. Summer Rain.

b