You will be given a definition of a task first, then some input of the task.
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: Tom parked his car at an incline. Sentence 2: It was a manual transmission. Sentence 3: Tom forgot to put the emergency brake all the way up. Sentence 4: When he walked away the car started to roll downhill. Sentence 5: Luckily Tom was able to stop it in time. Choices: a. Runaway Car. b. Bumper Boats.
Output:
a