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: Cindy was drinking a glass of Guarana Antartica. Sentence 2: Someone asked her what it was. Sentence 3: She said it was Guarana Antarctica, the taste of Guarana. Sentence 4: They asked her what Guarana was. Sentence 5: She had to admit she had no earthly idea. Choices: a. The missing cookies. b. Guarana.

b