Just send the form in with the questions unanswered, by sending in the form you are replying.
I was hasty in urging the recipient to shred this intrusive piece of busybody mail. We should have a contest to find the most ... creative ... way to comply with the law. I like the idea of completing it in crayon, complete with stick-figure drawings, dog poop stains, and a return envelope stuffed full of coupons for adult escort services. The first two become especially poignant when they read the questionnaire and discover that there are no children or pets in the household, except for Algernon the Mouse.