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: My 99 year old friend Ben sits on the bench a lot. Sentence 2: Yesterday he told me he had enrolled in some courses. Sentence 3: Brandeis has courses open for senior citizens. Sentence 4: I asked him why he wanted to go to so many courses. Sentence 5: He said if he keeps busy he won't die. Choices: a. Classes. b. Guilty.

a