However, I don't think questions of that particular sort should be answered in earnest.
Instead I would recommend a "gentle hand" sort of verbal Aikido, where you answer with a question.
"What makes you ask that?" Spoken with an accomodating, friendly tone.
And every answer you get, ask a why or howcome or otherwise.
Accomodating, gentle.
You don't have to answer the question until you are certain that it is asked in good faith, and you find that out by asking for reasons and reasonings.