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: Barry found an optical illusion. Sentence 2: He stared at it for a while. Sentence 3: He couldn't see the trick. Sentence 4: He realized he was blinking. Sentence 5: He stopped that. Choices: a. Tools. b. Blinking.
Output:
b