Trying to come up with the most legible sans-serif question mark for my Google reCAPTCHA's help icon. The ones that Google use are either too retro or too unreadable (below).
I want a question mark that is so clear at such a tiny size, yet so similar to standard sans-serif that my users immediately will understand what it's about instead of getting hung up on the design itself. It should be aliased for maximum clarity. I've tried Miniml, redrawing Helvetica etc., but I just can't come up with one that feels right.