“I’d rather not say” is an answer. Practice it until it comes out easy.

A question does not create an obligation, though it certainly feels like one, especially when the person asking is older or in charge of something. Declining to answer is itself a complete answer. What makes it hard is unfamiliarity rather than rudeness: the words feel wrong the first few times you use them, and then they stop feeling like anything, the way new sentences do.

Rehearse it out loud where nobody can hear, which sounds silly and works. Then use it this week on something low stakes, a question about money or a grade. Starting small is how you get it ready for when it matters.