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: Gregory had never taken a train in his life. Sentence 2: So when he was on his first train, he was surprised how fast it went. Sentence 3: He looked outside the window and everything was a blur. Sentence 4: When he climbed down, he was very satisfied. Sentence 5: He decided to do all his travel by train from now on. Choices: a. Mud lover. b. Discovering trains.

b