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: When Jack was young he wanted to be a bonsai master. Sentence 2: When he was 18 he moved to Japan to pursue his dream. Sentence 3: He studied under bonsai masters from Asia and Europe. Sentence 4: When he came home he used his new knowledge to start a bonsai nursery. Sentence 5: He is extremely happy now, surrounded by bonsai everyday. Choices: a. Bonsai boy. b. Thunder.

a