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: Paul decided to find out about his birth parents. Sentence 2: He asked his adoptive parents about them. Sentence 3: They told him his mother had been a prostitute. Sentence 4: Paul looked at them stunned. Sentence 5: He decided not to ask them who his father had been. Choices: a. There's A Reason It's Hidden. b. Cigar Box.

a