Challenge questions are a series of questions used to verify your identity or test your knowledge on a specific topic. They are meant to provide an extra layer of security or assess your understanding in a particular area. Full definition
Now however I see it as using the wonderful gift of humor to struggle with one of the more challenging questions of the Christian faith. (nakedpastor.com)
We need people who aren't afraid to ask challenging questions about sacred cows. (redeeminggod.com)
The first page breaks the questions down into clear steps while the second page includes more challenging questions with less support. (tes.com)