Should "à" be translated to "in" (as in the given answer), "about", or even "by"?
Just curious also as to why this wasn't accepted; is there a better way to say this phrase in French in general?
I think something like "Tu n'as aucun intérêt pour rien" would be a more accurate translation of your english sentence.
Not 100% sure on the pronoun in that french translation tho. Someone may need to correct me