I will call it just "asset", fiat isn't asset because it has no value, instead it just most people trust fiat for thinking it has a value.
Hahaha...Regardless of what you think, fiat is an asset, and I hope you do not state otherwise in an exam, there are too many to prove that, so don't let us go there. The issue is that the asset is tied to a particular country's economy, which makes it very unreliable.
Bitcoin and gold price moves different, Bitcoin mostly affected by trend, while gold is very well known asset which people not scare to buy at which price and mainly during crisis.
Gold and Bitcoin move with trends and events, it's wrong to say otherwise of Gold. Just like any asset, Gold does not buy only during the period of crisis, the same way that Bitcoin will not always sell because of a crisis. Many macro and microeconomic events affect all these assets, but the peculiarity here is that both Gold and Bitcoin are of different asset classes. Gold is risk-off, while Bitcoin is risk-on. That's why they behave differently in some situations.