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: The boy learned to count to ten. Sentence 2: His mom challenged him to count higher. Sentence 3: He tried making up his own numbers. Sentence 4: His mom thought that was pretty good. Sentence 5: She gave him a nice sticker as reward. Choices: a. Bomb. b. Counting.

b