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: Yorick was quite fearful, but hid this from his friends. Sentence 2: His external emotions rarely reflected how he truly felt. Sentence 3: He went to visit a cavern with some friends. Sentence 4: He was particularly afraid of dark caverns. Sentence 5: He yelped when they turned out the lights, shocking his friends. Choices: a. Air. b. Yorick's Yellow Yell.

b