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: Lucy had two pet rabbits. Sentence 2: She left them with her dad when she went on vacation. Sentence 3: To his surprise, babies appeared the next day. Sentence 4: Lucy's dad suddenly had his hands full with baby bunnies. Sentence 5: As is turns out, Lucy's rabbits were male and female. Choices: a. A Muscle Car. b. Baby Bunnies.
Output:
b