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: Olaf was a computer programmer. Sentence 2: He was tasked with discerning humans from bots. Sentence 3: He wrote a program that required humans to copy text from images. Sentence 4: It was successful but greatly annoyed users. Sentence 5: Olaf was satisfied with his work overall. Choices: a. The phone. b. Bot-checking.

b