Read the excerpt from a letter What is the author's purpose?

Parkour, also known as free running, is becoming a
popular sport. The object of parkour is to navigate
obstacles using fluid, efficient movement. Athletes run
through urban areas using gymnastic-type leaps and
jumps to move over and around walls, ledges, and
other barricades. The sport's name originates from
parcours du combattant, an obstacle course used to
train soldiers in the French army.
O to entertain the reader with an interesting story
O to provide examples of parkour movements
O to educate the reader about a popular sport
O to persuade readers that parkour is dangerous