Given the task definition and input, reply with output. 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'.

Sentence 1: The student council were having a hard time deciding on themes. Sentence 2: They wanted their prom to be memorable but very fun. Sentence 3: Some of the suggestions got voted down for being too cliche. Sentence 4: Others got voted out for being too outlandish. Sentence 5: They finally decided to have a Disco theme. Choices: a. Prom theme. b. Road Trip.
a