Given the task definition and input, reply with output. 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'.

Sentence 1: Bob bought an oil change business on a busy highway. Sentence 2: Very few people came to his business. Sentence 3: He decided to advertise his business in the local paper. Sentence 4: He ran an ad that offered discounts and promotions. Sentence 5: His business picked up tremendously. Choices: a. Bob's Oil Changes. b. Waiting for Bertha.
a