Those decisions are a lot easier for an adult to make than a student, a child. I actually got into this situation last night with my own.
She, in second grade, brings home a flyer with a thing the class is doing next Tuesday. Apparently they want to make some sort of presentation to the district school board to showcase how the class is doing and show "outcomes" in education.
The way this looks and sounds to me is that they're trying to justify something to the school board. Maybe it's a way to justify more funding, maybe it's to show that their investment last year is paying off. Who knows, but to me it sounds political. I don't really want my daughter involved in someone's political scheme. She doesn't know any better now, but when she gets older she'll look back negatively upon it when she has that mental review later on.
Anyway, I express this in the house and my wife understands. My wife can't participate anyway for another reason, a previous engagement outside the home. All my daughter hears is, "you won't let me go and I want to go do this thing!" I can't explain it, she can't understand. Even if she could, I don't really want her to have that negative feeling about her teacher or, even worse, the school. That's also a terrible way to grow up, that was me from a stupid young age.
Then don't go to the dance. It's not a trick question or whatever.