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: Ben decided to do some yard work over the weekend. Sentence 2: He spent a lot of time bending over to pull weeds. Sentence 3: When he got up Monday morning, Ben was in severe pain. Sentence 4: Ben's back hurt because of the strenuous yard work. Sentence 5: Ben had to take the day off to help his back recover. Choices: a. Ben's Bad Back. b. Karina And Her Blocks.

a