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: Joanna was nervous. Sentence 2: She was ready to go, but still kind of scared. Sentence 3: She was getting to ride on her first horse. Sentence 4: Up she went as she got on the horse's' back. Sentence 5: She had so much fun that day, riding the horse around the paddock. Choices: a. Her First Ride. b. The Research Project.

a