B.carefree days of a happy childhood
The passage lists the different activities the boys used to do: fly kites and sword fight with sticks. The author's word choices of "frolic", "play", "leaping", "easy" and others all show the carefree nature with which the boys played. The passage does not include any information about their dreams or relaxing. Also, even though the boys do compete against each other with their duels, the passage is not about the duel, but rather the pretend play.