Which story features a dynamic character?

In the beginning of the story, Teddy refuses to pass the soccer ball to his teammates and gets angry when his team loses. At the end of the story, Teddy realizes that friendship and teamwork are more important than winning.
In the beginning of the story, John sits at the edge of the pool and watches his friends have a good time swimming. At the end of the story, John complains of a stomachache when it is time for swimming class.
In the beginning of the story, Luis helps his little brother with his math homework. At the end of the story, Luis teaches his youngest brother how to ride a bicycle without training wheels.
In the beginning of the story, Tamara teases Phoebe about the low score she receives on a math quiz. At the end of the story, Tamara laughs at the way Paul holds a tennis racquet in gym class.