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 took his girlfriend to the zoo. Sentence 2: She had never been to any kind of wildlife preserve. Sentence 3: Tom felt proud as he showed her the beautiful animals. Sentence 4: Then they saw two zebras in an open field mating in front of everyone! Sentence 5: Tom never took a girl to a zoo again. Choices: a. Pool. b. Animal Instinct.
b