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: Bob has always wanted to become a history teacher. Sentence 2: He worked very hard to become one. Sentence 3: Bob finally became a history teacher. Sentence 4: He loved to teach his students. Sentence 5: He was happy that he had become a history teacher. Choices: a. Bob Teaches History. b. Ryan Writes A Letter.

a