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: Greg decided he was going to leave Sonya. Sentence 2: He had been unhappy for a long time. Sentence 3: He realized that it would probably never get better. Sentence 4: Greg wasn't sure what he was going to say to Sonya. Sentence 5: Greg packed his stuff and left without telling her. Choices: a. Leaving. b. Missed the bus.

a