If someone asks a simple question, it’s great - because most likely executives will have the exact same question, but depending on your relationship with them, it could go a few ways (or more): 1) they just think you don’t get it because they assume the answer to the basic question and it’s not the assumption you’re operating off of 2) they call you on it during the presentation and make it look like you have failed to explain the fundamentals 3) they wait until after the presentation to ask the question, and others in the room aren’t really sure about it either, because you just assumed everyone knew.

I think it’s OK to ask dumb questions twice. If you don’t get it by the third time (or fail to remember), then we might need to step back and revisit fundamentals, or your mental model might need adjustment so that the information makes sense in context.