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: Mary was running to catch the bus. Sentence 2: She was late for an appointment. Sentence 3: She tripped and fell. Sentence 4: The bus left without her. Sentence 5: A friend of Mary's drove her to her appointment. Choices: a. The Appointment. b. The Doctor..

a