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: Kim was having a kid. Sentence 2: She didn't know the sex. Sentence 3: Her doctor offered to tell her. Sentence 4: Kim agreed to it. Sentence 5: She was happy with the response. Choices: a. Unknown Sex. b. Pizza.

a