The corrcet answer would be relational.
Core. It sounds the same, but it is a completely different word.
The theme of the story is to not trust everything that's out there. In the beginning of the story, Derek believed that he was going to be able to get a Gamebox 9000 for free by doing all of these requirements. By the third tier, that is when he realized that it was all a scam. This story shows readers that not everything should be trusted.