Saying “that’s a good question” to the kid who finally raised their hand might be why they raise it again.

Whether a first attempt gets met decides whether there will be a second. Raising a hand after a long silence carries real risk, and the reply is read as a verdict on the decision to speak at all, not just on the question. Four words of encouragement cost nothing and settle it in the right direction. What happens next time was decided here.

Respond warmly to whoever speaks up, especially when the question is basic. Say specifically what was good about it. Do the same for the quiet colleague, the new person, and anyone taking a first run at something.