I think the better option is to ask questions that don't have one correct answer? Those are the hardest ones anyway, and the most relevant to the real world. Y

I think the better option is to ask questions that don't have one correct answer? Those are the hardest ones anyway, and the most relevant to the real world. You explore the options beforehand, and try to figure out benefits / drawbacks. Then when you ask the question, you see if people see those tradeoffs too. Even better, you pose the question slightly differently each time, such that a different option is more favored every time. This filters out people who think they have the "right" answer. Who knows - one day a candidate could even surprise you with an answer you didn't think of!