> "I’m a privileged white seventeen-year-old U.S. male."
I think it has the air of a trick question though. Most readers will (correctly) assume that Hal is white, which the text does little to dispute or confirm barring a throwaway reference or two (and which is unlikely to stand out in their minds since it confirms what they already assumed), so encountering such a question makes it seem like the answer is more complicated than "Shockingly, the tennis heir protagonist written by a white American author is also a white American kid." And for many people it's somewhat gauche to admit that you assumed a character was white by default, so if you hazard a (correct) guess of "Well he's white, isn't he?" but it turns out there was a different throwaway reference to him being a quarter Puerto Rican or something, you might be a little embarrassed!
EDIT: I forgot there is actually a throwaway reference to Hal being (at most) 1/8th Native American, lol.
> ...a great-grandmother with Pima-tribe Indian S.W. blood, and Canadian cross-breeding...