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: Jenny is four years and two weeks old. Sentence 2: She started a swimming class for four year olds last week. Sentence 3: She was better at swimming than the other children. Sentence 4: Her teacher promoted her to the next class up. Sentence 5: Jenny was given a badge and was very happy. Choices: a. Little swimming star. b. Ants.
a