The correct answer is The Kentucky Derby.
In 1883, red roses were given to all of the ladies who attended one of the fashionable Derby parties in Louisville. The roses were such a success that Churchill Downs President, Colonel Lewis Clark decided to make it official for the next year´s running. By 1904 the red rose had become the official flower of the Kentucky Derby. The rose garland is also the source for the nickname Run for the Roses.